Platinum Metals Review · 2016. 1. 28. · Platinum Metals Rev., 2007, 51, (4) 166 (discussed in Part I (1)), and the process enhance-ments resulting from the move from gas to liquid

PlatinumMetalsReview

www.platinummetalsreview.comE-ISSN 1471–0676

VOLUME 51 NUMBER 4 OCTOBER 2007

E-ISSN 1471–0676

PLATINUM METALS REVIEWA Quarterly Survey of Research on the Platinum Metals and

of Developments in their Application in Industrywww.platinummetalsreview.com

VOL. 51 OCTOBER 2007 NO. 4

Contents

Enhancement of Industrial Hydroformylation Processes 164by the Adoption of Rhodium-Based Catalyst: Part II

By Richard Tudor and Michael Ashley

Novel Chiral Chemistries Japan 2007 172A conference review by David J. Ager

“Recent Developments in the Organometallic Chemistry 176of N-Heterocyclic Carbenes”A journal synopsis by Robert H. Crabtree

Annealing Characteristics and Strain Resistance 178of 99.93 wt.% Platinum

By Yu. N. Loginov, A. V. Yermakov, L. G. Grohovskaya and G. I. Studenok

40th Conference ‘Deutscher Katalytiker’ 185A conference review by Thomas Ilkenhans

“Metal-catalysis in Industrial Organic Processes” 187A book review by Robin B. Bedford

Building a Thermodynamic Database for 189Platinum-Based Superalloys: Part II

By A. Watson, R. Süss and L. A. Cornish

The 21st Santa Fe Symposium on Jewelry 199Manufacturing Technology

A conference review by Christopher W. Corti

“Combinatorial and High-Throughput Discovery 204and Optimization of Catalysts and Materials”

A selective book review by Kim Chandler, Ann Keep,Sue Ellis and Sarah Ball

Abstracts 208New Patents 212

Indexes to Volume 51 215

Communications should be addressed to: The Editor, Barry W. Copping, Platinum Metals Review, [email protected]; Johnson Matthey Public Limited Company, Orchard Road, Royston, Hertfordshire SG8 5HE, U.K.

Platinum Metals Rev., 2007, 51, (4), 164–171 164

DOI: 10.1595/147106707X238211

The ‘Low Pressure Oxo’ process (LP OxoSM

Process) was developed and then licensed to the oxoindustry through a tripartite collaboration beginningin 1971. The principals were Johnson Matthey & Co.Ltd. (now Johnson Matthey PLC), The Power-GasCorporation Ltd. (a former name of Davy ProcessTechnology Ltd., now a subsidiary of JohnsonMatthey PLC) and Union Carbide Corporation (nowa subsidiary of The Dow Chemical Company). Usingrhodium-based catalysis, the LP OxoSM Processoffered such great economic advantages over theestablished cobalt-catalysed processes, as well astechnical elegance, that many cobalt systems werereplaced by brand new plants. In the thirty years orso since the LP OxoSM Process was first introduced,it has maintained its position as the world’s foremostoxo process, having undergone much improvementand refinement. About two thirds of the world’sbutyraldehyde is now produced in LP OxoSM plants.Most LP OxoSM systems are licensed plants, nearly allof which have been built under licences granted byDavy Process Technology (2) working in coopera-tion with The Dow Chemical Company (3); theremainder are plants owned and operated by Dow’sUnion Carbide subsidiary (4).

The first commercial plant to use the LP OxoSM

Process was a unit built by Union Carbide at Poncein Puerto Rico for producing 136,000 tonnes perannum of butyraldehydes. The Ponce plant startedoperation in 1976. By the end of 1982, Davy ProcessTechnology had licensed and designed ten LP OxoSM

plants that were built around the world. All theseplants employed a homogeneous triphenylphos-phine (TPP)-modified rhodium catalyst, and in situgas stripping was adopted to separate the butyral-dehyde product from the rhodium-containing cata-lyst solution which remained in the oxo reactor. (Theflowscheme for an LP OxoSM plant employing thisgas recycle principle is described in Part I (1).)Adopting gas recycle not only led to a simple andaffordable process flowsheet, it also provided thebest overall working regime for the catalyst, in termsof both loss prevention and deactivation, based onthe ‘state of the art’ at the time.

From Gas to Liquid RecycleOnce the gas recycle technology had been

proven, and market interest in the LP OxoSM Processwas intensifying, Union Carbide and Davy ProcessTechnology turned their attention to a new

Enhancement of IndustrialHydroformylation Processes by theAdoption of Rhodium-Based Catalyst:Part IIKEY IMPROVEMENTS TO RHODIUM PROCESS, AND USE IN NON-PROPYLENE APPLICATIONS

By Richard Tudor* and Michael AshleyDavy Process Technology Ltd., 20 Eastbourne Terrace, London W2 6LE, U.K.; *E-mail: [email protected]

Part I of this article (1), which appeared in the July 2007 issue of Platinum Metals Review,described the substantial cost and technical benefits brought to the hydroformylation ofpropylene with carbon monoxide and hydrogen (an ‘oxo’reaction) by replacing the previoushigh-pressure cobalt-catalysed technology with a low-pressure rhodium-based catalyst system(the LP OxoSM Process). The background to the rhodium process and its development to thepoint of first commercialisation were reviewed. This article (Part II) covers some of theimprovements made to the LP OxoSM Process after the early plants started operation, and itsuses in non-propylene applications.

Platinum Metals Rev., 2007, 51, (4) 165

flowsheet concept employing the ‘liquid recycle’principle. This involved separating the reactionproduct from the catalyst solution in equipment out-side the oxo reactor, using a sequence of vapourflashing (resulting from an abrupt pressure reduc-tion) and vaporisation using a suitable external heatsource. Reaction solution from the back-mixed reac-tor was continuously fed to this equipment, in whichthe greater part of the butyraldehyde and reactionbyproducts present in the feed were separated fromthe rhodium-bearing catalyst solution, which wasrecycled to the reactor. The net rate of removal byexternal vaporisation of products and byproductsmatched their rate of production in the reactor, so asto maintain a constant catalyst solution inventory.The liquid recycle flowsheet also included the meansto recover and recycle dissolved reactants present inthe separated product stream.

Apart from these basic principles of liquid recy-cle, much attention had to be given to the operatingconditions under which vaporisation of productswould occur, particularly the duration for which cat-alyst would be exposed to a raised temperatureoutside the equable environment of the reactor.Earlier deactivation studies in the laboratory and thesuccessful operation of the Ponce plant had givenvaluable insights in this regard. It had become evi-dent that decomposition of the triphenylphosphine(TPP)-rhodium complex – a potential concern –should be avoidable. A proprietary vaporisation sys-tem design emerged from the efforts of specialistengineers working alongside the process developers.

The overriding merit of the liquid recycleapproach was that by decoupling the hydroformyl-ation reaction step from the physical process ofproduct/catalyst separation, it became possible toadopt operating conditions in the reactor to optimisethe balance of production rate (or reaction ‘speed’),selectivity and (catalyst) stability – the ‘three Ss’. Thetechnique adopted exemplified the challenge facingthe developers and designers of commercial liquidphase homogeneous catalyst systems, that of balanc-ing the ‘three Ss’ by imaginatively addressing theissue of product/catalyst separation. Here, decou-pling reaction from separation would, for example,obviate the necessity to run the reactor at tempera-tures dictated by product stripping requirements.

The introduction of liquid recycle therefore pro-vided the plant operator with more degrees offreedom to get the best performance from an oxoreaction system than hitherto had been possible. ForDavy Process Technology and Union Carbide, itwould open up new possibilities for the LP OxoSM

Process in terms of catalyst selection and its applica-tion with olefins other than propylene.

Another advantage of the liquid recycle approachwas that the oxo reactor could be reduced in size.With gas recycle, it was necessary to allow a signifi-cant excess reaction volume, to accommodateexpansion of the liquid phase by the entrainment ofbubbles from a large gas flow. With no such gas flowrequired with liquid recycle, most of this volumeallowance could be dispensed with. This was partic-ularly significant for gas recycle plant operators whohad decided to enlarge their production capacities.By converting their plants from gas to liquid recycle,they could almost double the production capacitiesof their existing oxo reactors.

With oxo plants becoming larger in size, theadoption of liquid recycle resulted in designs oflower cost, mainly as a result of the elimination ofthe cycle compressor and the use of smaller reactors.Practically all LP OxoSM plants designed since themid 1980s employ liquid recycle, to which several ofthe early gas recycle designs have also been con-verted. Plant operators welcome the added operatingflexibility, enabling them to optimise reaction con-ditions to their production capacity and productmix requirements.

The Introduction of a Bisphosphite-Modified Rhodium Catalyst

A continuing programme of investment by DavyProcess Technology and Union Carbide in researchand process development aimed at improving andrefining the LP OxoSM Process, coupled with thesubstantial operating experience accumulated fromUnion Carbide’s own oxo plants and more thantwenty plants built by others under licence, have,over the years, resulted in considerable improve-ments to the original process. The technical andcommercial appeal of the LP OxoSM Process overcompeting processes has, if anything, increased. Thediscovery and successful use of catalyst reactivation


(discussed in Part I (1)), and the process enhance-ments resulting from the move from gas to liquidrecycle are just two examples of the improve-ments made.

The quest for improvement has not been con-fined to the TPP-modified rhodium system. Today,several LP OxoSM plants are producing butyralde-hyde using a more advanced bisphosphite-modifiedrhodium catalyst developed by Union Carbide. Thechemical characteristics, intrinsic activity, stabilityand regioselectivity of this catalyst show marked dif-ferences from those of the TPP-modified catalyststill used in most operating plants. The challenge ofrecent years has been how best to capitalise on theexcellence of some attributes of bisphosphite cata-lysts where it most counts, i.e. in terms of feedstockutilisation efficiency, selectivity to normal butyral-dehyde, rhodium inventory and catalyst life.

It had been known for many years before theintroduction of bisphosphites that phosphite-modi-fied rhodium catalysts are very reactive and showgood regioselectivity (i.e. selectivity to the straightchain aldehyde) in comparison with phosphine-modified catalysts. Conventional phosphites,however, had been found to be unstable in the pres-ence of aldehydes. This limitation was overcomethrough the development of bisphosphite ligands.

The preparation, structural features and perfor-mance in hydroformylation by bisphosphites werediscussed by Union Carbide’s David R. Bryant at theRoyal Society of Chemistry Dalton Division’sFourth International Conference on the Chemistryof the Platinum Group Metals in 1990 (5, 6). Then,

in 1992, at a meeting of the American ChemicalSociety (7), Dr Bryant discussed the new-foundplace for bisphosphite-modified rhodium catalysts,describing them as the fourth generation of oxo cat-alysts, following the first-generation unmodifiedcobalt, then phosphine modified cobalt, then phos-phine-modified rhodium catalysts. Several UnionCarbide patents (e.g. 8–10) disclosed a large numberof bisphosphite-modified rhodium catalyst systemsthat are much more active than those based on TPP,with much higher selectivity to the linear aldehydepossible. Certain Union Carbide patents also gavemethods for stabilising bisphosphite-modifiedcatalysts.

Preparing the bisphosphite ligands from substi-tuted biphenols imparts the high degree of sterichindrance needed to achieve the good regioselec-tivity sought in some hydroformylation applications,for instance in the production of butyraldehydes.

The molecular structure of TPP and a generalrepresentation of a bisphosphite are shown in Figure1. The chemical nature of the group bridging thetwo phosphite groups has a crucial bearing onhydroformylation performance. The bridge could bespecifically configured to encourage high normal toiso selectivity at an acceptable reaction rate by theappropriate choice of substituents X3, X4, Y3 and Y4

in Figure 1.It is thought that the bisphosphite ligand func-

tions in a hydroformylation environment by doublycoordinating rhodium to form a bidentate complex.The favourable steric environment thus createdaround the rhodium is the likely cause of the high

Fig. 1 Structures of triphenylphosphine and bisphosphite ligands. For butyraldehyde production, highnormal to iso selectivity at an acceptable reaction rate is encouraged by the appropriate choice ofsubstituents X3, X4, Y3 and Y4

PY2

X1

X2

Y1

O

OP

O O

Y3 Y4

X3 X4

PO

O

X5

X6

Y5

Y6

Triphenylphosphine Bisphosphite


regioselectivity mentioned above.Union Carbide found that with propylene, it was

possible to select in the laboratory a suitable bispho-sphite-modified rhodium catalyst that would showabout 30 times the activity of a TPP-modified cata-lyst, while achieving extraordinarily high selectivity tonormal butyraldehyde and using lower ligandconcentrations. Since bisphosphite-liganded catalystcomplexes were viewed as having great potential,Union Carbide had devoted a substantial R&D effortto resolving issues over their stability in commercial hydroformylation environments. UnionCarbide were confident that they had found a way forward to the first commercial use of these catalysts.

The successful adoption of the liquid recycle prin-ciple in many operating LP OxoSM plants by the early1990s had opened the way to specifying a commer-cial propylene hydroformylation process in-corporating a bisphosphite-modified catalyst thatwould offer much appeal over its TPP counterpart.On the basis of test work they had performed in thelaboratory, Union Carbide believed that they had dis-covered how best to utilise and sustain the highactivity of bisphosphite-modified catalyst in acommercial environment. The first commercial plantto use the catalyst system was built by Union Carbideat its petrochemical complex at St. Charles, Louisiana,U.S.A., for producing 136,000 tonnes per annum ofbutanol from propylene. Production started in 1995.

In designing the plant, the concentration of rhodi-um in the catalyst was set at about one third of thatfor a TPP-modified catalyst system, and the operat-ing temperature of the catalyst and the reactionpressure were reduced. Catalyst productivity, relatingthe rate of production to catalyst volume, was notaltered drastically from that for which the TPP-mod-ified catalyst plants had been designed. It was thoughtbetter to exploit improved catalyst activity by reduc-ing the rhodium inventory and in reducing byproductformation to improve feedstock efficiency, ratherthan by making reactors smaller. In selecting theoperating temperature, known factors influencingcatalyst stability were also considered.

The Dow Chemical Company, which acquiredUnion Carbide in 2001, today operates two plants atthe St. Charles site employing the LP OxoSM Process

using LP OxoSM SELECTORSM Technology, using aproprietary bisphosphite-modified rhodium catalyst.Further plants have been licensed to deploy the samecatalyst system, one of which operates in Malaysia;the latest SELECTORSM 30 licence was granted ear-lier this year (2007) for a butanols plant to be built inthe Kingdom of Saudi Arabia. The bisphosphite isintroduced to the process as the NORMAXTM

Catalyst compound, which is available from TheDow Chemical Company.

The experience gained from more than elevenyears of operation of the first St. Charles plant andprocess refinements made in recent years have pro-vided the technical platform for the ‘SELECTORSM

30’ Technology that Davy Process Technology offersfor licence in collaboration with Dow. The brandname is derived from the ratio of normal to iso-butyraldehyde of 30:1 that the process is capable ofachieving through the use of NORMAXTM Catalyst.

While the SELECTORSM 30 Technology hasaroused much interest, Davy Process Technologyand Dow are seeing a sustained interest in the TPP-modified catalyst technology for use in propyleneapplications. This is now marketed under the brandname ‘SELECTORSM 10’ Technology. As the nameimplies, this refers to the normal to iso ratio of 10:1with which the TPP process is usually associated. Justthis year (2007), Davy Process Technology granted alicence to a Chinese company for a plant for produc-ing approximately 250,000 tonnes per annum in totalof 2EH and normal plus iso-butanols employingSELECTORSM 10 Technology. This will be thelargest LP OxoSM plant in Asia.

TPP or Bisphosphite?Many factors influence the choice of route for

producing oxo derivatives from propylene, and thefollowing highlights some of the parameters onwhich the choice of ligand can have a significant bear-ing.

The NORMAXTM Catalyst today offers the high-est commercially proven isomer selectivity in favourof normal butyraldehyde production. The SELEC-TORSM 30 Technology will therefore appeal stronglywhere the production of 2-ethylhexanol (2EH) fromthe available propylene is to be maximised. Putsimply, production of 2EH using SELECTORSM 30


will typically consume between 6 and 7% less pro-pylene than with SELECTORSM 10, solely as a resultof the improved selectivity of conversion to the nor-mal aldehyde. Further improvements in efficiencycan result from the reduced formation of byproductsarising from the lower operating temperatures usedwith the NORMAXTM Catalyst as compared withTPP, and also because of lower propylene purgelosses. Plant owners having access to lower-grade,cheaper propylene streams, may also find theNORMAXTM Catalyst system attractive because itshigh activity will effectively handle dilute feed-streams, such as refinery-grade propylene.

Questions concerning the stability of bis-phosphite-modified rhodium catalysts in commercialservice (and there were many!) have been conclusive-ly answered by excellent experience with those plantsnow using NORMAXTM Catalyst. This has indicatedthat exceptional rhodium catalyst life can be expect-ed. In the more than eleven years since the first LPOxoSM plant utilising NORMAXTM Catalyst wentinto operation at St. Charles, no replacement of theoriginal oxo catalyst charge has been necessary.Furthermore, the rhodium usage has been extremelysmall. The same picture has emerged for the secondSt. Charles plant and the licensed plantin Malaysia.

The manufacturing cost per kilogramme ofNORMAXTM Catalyst is higher than that of TPP.The cost difference is largely compensated for by thelarge differences in the quantities of these ligands thatare needed to operate commercial plants. This isbecause the benefits of the bisphosphite-modifiedcatalysts are best realised with the ligand present atmuch lower concentrations in the catalyst solutionthan is the case with TPP-modified systems.Experience has shown that for commercial pro-pylene systems, the contribution to the cash cost ofproduction by rhodium and ligand for theSELECTORSM 30 Technology is very comparable toits equivalent for SELECTORSM 10. Typically, forthe TPP system, the contribution is about U.S.$2 toU.S.$3 per tonne of butyraldehyde, whereas for systems employing NORMAXTM Catalyst, it is aboutU.S.$5 per tonne.

Other factors are influencing licensees of the LPOxoSM Process in their choice of ligand. The highest

possible selectivity to normal butyraldehyde is notalways the priority. Some oxo producers desire toproduce iso-butyraldehyde to make derivatives suchas neopentylglycol, for use in speciality polyesters, orother polyols going into, for instance, volatile freefilm-formers. The NORMAXTM Catalyst would beinappropriate in such cases. The butyraldehyde sec-tion of a 2EH plant licensed in 2003 by Davy ProcessTechnology was designed to use TPP with the capa-bility of being able to vary the normal to iso productratio from 12:1 to only 6:1 – to provide good flexi-bility in the amount of iso-butyraldehyde coproduct.

The Influence of Rhodium MetalPrices

The price of rhodium metal has varied enormous-ly in the forty years since rhodium first attractedserious attention for hydroformylation catalysis. Thisvariation is plotted in Figure 2 (11, 12).

Rhodium is presently more than 25 times moreexpensive in U.S. dollar terms (11, 12) than it waswhen the strong economic drivers for rhodium firstemerged in the early 1970s. While for plants operat-ing the LP OxoSM Process, the variable costcontribution from rhodium is often barely U.S.$1 pertonne of product, which is extremely modest, therhodium price can have a large impact on the work-ing capital needed for a new plant investment. In theearly 1990s, the monthly rhodium metal price, havingnever previously been more than U.S.$2000 per troyounce, quite quickly rose to about U.S.$5000 per troyounce (12), where it remained for almost a yearbefore easing right back to well below U.S.$1000 pertroy ounce. This increase in the rhodium price wouldhave caused concerns among those companies con-templating investing in TPP/rhodium-basedtechnology. Furthermore, it stimulated UnionCarbide and Davy Process Technology into planningmore proactively for a ‘low rhodium’ version of theLP OxoSM Process. Fortunately, at the time, the low-rhodium solution was already under development inthe form of a modified version of the LP OxoSM

Process using a more advanced bisphosphite-modi-fied catalyst.

To put the effect of the rhodium price into a pre-sent-day perspective, even priced at U.S.$5000 pertroy ounce (the rhodium price at the time of writing


(early July 2007) is about U.S.$6150 (12)), the cost tothe plant operator of the least amount of rhodiumpossible to start a 150,000 tonnes per annum 2EHplant using SELECTORSM 10 Technology is in theorder of U.S.$9 million, which is more than 10% ofthe inside battery limit (ISBL) investment cost. Inpractice, the operator would probably wish to keepadditional rhodium in reserve. Over a period ofyears, the rhodium inventory might well build to typ-ically about one and a half times the initialrequirement. The SELECTORSM 30 technology hasthe advantage that, with lower concentrations ofrhodium used, the rhodium inventory of a plant canbe reduced to less than one third of that needed forSELECTORSM 10.

With the rhodium price now having remained rel-atively high at over U.S.$4500 per troy ounce forover a year (12), some operators of the TPP-basedSELECTORSM 10 Technology will be considering aswitch from TPP to the NORMAXTM Catalyst. If amuch improved selectivity to normal butyraldehydeis a sufficient incentive, they could find that the assetvalue of surplus rhodium presently locked into aTPP-modified catalyst system (but recoverable fromit) could easily pay for a project to convert theirplants to SELECTORSM 30.

With product values (on a U.S. dollar per tonnebasis) at best only quadrupling since the early 1970s,a 25-fold, even 10-fold increase in rhodium pricesover the same period might have been expected to

undermine the sustainability of a commercial petro-chemical process based on rhodium chemistry. Inthe case of the LP OxoSM Process, this situation hasbeen avoided through advances in the technologysuch as those described in this article. The advanceshave tended to reduce the investment capitalrequired per tonne of product, and have at least part-ly mitigated the requirement for extra workingcapital to establish rhodium inventories. Theadvances have also resulted in significant improve-ments in operating costs. The net effect of this is thattoday, oxo alcohols can be manufactured frompropylene at a lower cost in real terms than everbefore, despite the relatively high cost of raw materi-als resulting from expensive oil and the current levelof the rhodium metal price. This cost-effectivenesshas resulted not only from ingenious rhodium chem-istry, but also from essential contributions fromchemists, process developers and designers, not for-getting the plant operators.

LP OxoSM TodayThe Dow Chemical Company and Davy Process

Technology collaborate through their respectivelicensing organisations to market and license LPOxoSM Technology for use with propylene in plantsemploying either SELECTORSM 10 (TPP) orSELECTORSM 30 (NORMAXTM Catalyst)Technology. SELECTORSM 10 is suitable for anormal to iso ratio requirement of between about 6:1

Fig. 2 Monthly rhodiumprices from January 1965to June 2007 (Source:Johnson Matthey PreciousMetals Marketing, U.K.)

7000

6000

5000

4000

3000

2000

1000

0Mon

thly

rhod

ium

pric

es, U

.S.$

per

troy

oz

Jan-65 Jan-75 Jan-85 Jan-95 Jan-05Date


and 14:1, and SELECTORSM 30 for between 22:1and 30:1. Based on laboratory trials, a ratio of at least35:1 is believed to be attainable commercially usingthe bisphosphite-modified rhodium catalystemployed in SELECTORSM 30 designs. As part ofthe LP OxoSM licence offering, technology is avail-able for the production from butyraldehyde of 2EH,normal butanol or iso-butanol in any combination.Most of the thirty or so propylene-based LP OxoSM

projects so far licensed involve 2EH and/or butanolplants designed by Davy Process Technology.

Other Applications of the LP OxoSM

ProcessThe investment by Davy Process Technology

and Union Carbide in research and process develop-ment has converted the early laboratory promise ofrhodium chemistry into commercial realities of wideappeal. The oxo landscape has eventually changed asa result. The ongoing quest for technical excellencedriven by the market for butyraldehyde and its deriv-atives has opened up applications for the LP OxoSM

Process for non-propylene uses.LP OxoSM Technology has been used to produce

from normal butenes commercial quantities of 2-propylheptanol (2PH), an alternative plasticiseralcohol to 2EH in which there is a growing interest.The commercial 2PH product actually contains 2-propylheptanol as the principal component in anisomeric mixture of C10 alcohols. The phthalateester plasticiser made from 2PH is often referred toas DPHP, or di(2-propylheptyl) phthalate. DPHP isgradually establishing a place in certain plasticisermarkets in Europe and the U.S.A. because of envi-ronmental and other factors. It offers advantages asa plasticiser for flexible PVC applications where itslow volatility, good long-term stability and excellentoutdoor performance can be exploited.

The 2PH technology developed by Davy ProcessTechnology and Union Carbide can operate withcommercial C4 streams containing 1-butene and 2-butene such as raffinate 2 streams available frommethyl tert-butyl ether (MTBE) plants. The highreactivity of a NORMAXTM bisphosphite-modifiedrhodium catalyst can be exploited so that both the 1-butene and the less reactive 2-butene present inthe feedstream contribute as valuable reactive feed

components to ensure the best available overallproduct yield. Where there is interest from a 2EHproducer in producing 2PH in order to exploit asuitable C4 feed source that is likely to be consider-ably cheaper than propylene, Davy ProcessTechnology is able to design an LP OxoSM plant thatis capable of producing either 2EH or 2PH separate-ly by switching between propylene and butenefeedstocks.

Should the 2EH/2PH producer have a particularrequirement to gradually ramp up production of2PH according to how the market is seen to devel-op, another possible approach is to produce the twoplasticiser alcohols simultaneously by co-feedingpropylene and butenes to the oxo system in appro-priate proportions, finally separating the 2EHproduct from the 2PH product. If a co-feed route isadopted, it would be necessary to conduct separatealdol condensation steps on separated C4 and C5aldehyde streams prior to a combined C8/C10hydrogenation step, in order to maximise yields ofdesired products.

LP OxoSM Technology has also been developedfor, and successfully operates under licence in, aplant for producing C12 to C15 surfactant rangealcohols from C11 to C14 olefins derived fromFischer Tropsch synthesis. The plant capacity is120,000 tonnes per annum. The technology is alsobeing applied in a 125,000 tonnes per annumprocess plant now in construction for converting 1-heptene (extracted from Fischer-Tropsch prod-ucts) to 1-octanol. The octanol product is to be usedin the production of co-monomer grade 1-octene.Both these applications of the LP OxoSM Processwere developed by Davy Process Technology at itsTechnology Centre at Stockton-on-Tees in the U.K.Figure 3 shows the ‘Mini-Plant’ employed forthis purpose.

ConclusionIn recent customer surveys made on behalf of

Dow and Davy Process Technology, operators ofthe LP OxoSM Process have commended the ease ofoperation and the low environmental impact of theplants, their high reliability and their low mainte-nance requirements.

A successful resolution of various issues in


rhodium catalyst management has been essentialto the commercialisation of the process. Thissuccess should provide convincing encouragementto researchers, who are keen to exploit pgms as cat-alyst materials, but who are apprehensive as to theimplications of their very high intrinsic value. Itshould also encourage developers and designers who

are entrusted with turning pgm chemistry intocommercial processes, but who may be dauntedby problems such as pgm containment andcatalyst life.

The LP OxoSM Process is recognised as one ofthe best known applications of industrial-scalechemistry using a pgm. The promise of rhodiumchemistry first observed forty years ago has trans-formed the manufacturing base of a petrochemicalsector. Davy Process Technology and The DowChemical Company are continuing in their efforts tobuild on and extend the significant contributionmade towards this transformation by the LP OxoSM

Process. Their market focus and continuing effortsin research and process development programmesdriven by a sustained market interest will likely meanthat the LP OxoSM Process will continue to play animportant role in industrial hydroformylation appli-cations for many years to come.

Fig. 3 Oxo ‘Mini-Plant’ at Davy Process Technology’sTechnology Centre, Stockton-on-Tees, U.K.

1 R. Tudor and M. Ashley, Platinum Metals Rev., 2007,51, (3), 116

2 Davy Process Technology Ltd.:http://www.davyprotech.com/

3 The Dow Chemical Company:http://www.dow.com/

4 Union Carbide Corporation: http://www.unioncarbide.com/

5 David R. Bryant and Ernst Billig, ‘Phosphites inHydroformylation’, in: Royal Society of ChemistryDalton Division, Fourth International Conferenceon The Chemistry of the Platinum Group Metals,University of Cambridge, Cambridge, U.K.,9th–13th July, 1990

6 C. F. J. Barnard, Platinum Metals Rev., 1990, 34, (4),207

7 David R. Bryant, ‘Four Steps in HydroformylationTechnology’, in: American Chemical Society 203rdNational Meeting, San Francisco, California, U.S.A.,5th–10th April, 1992

8 E. Billig, A. G. Abatjoglou and D. R. Bryant, UnionCarbide Corporation, ‘Transition Metal ComplexCatalyzed Processes’, U.S. Patent 4,668,651; 1987

9 E. Billig, A. G. Abatjoglou and D. R. Bryant, UnionCarbide Corporation, ‘Bis-phosphite Compounds’,U.S. Patent 4,748,261; 1988

10 E. Billig, A. G. Abatjoglou and D. R. Bryant, UnionCarbide Corporation, ‘Bis-phosphite Compounds’,U.S. Patent 4,885,401; 1989

11 Johnson Matthey Precious Metals Marketing, U.K.12 Platinum Today, PGM Prices, Current and Historical:

http://www.platinum.matthey.com/prices/current_historical.html

The AuthorsRichard Tudor is a chartered chemicalengineer. He has played a leading part in DavyProcess Technology’s oxo licensing activitiesfor over thirty years, firstly as ProcessManager, and then as Business Manager aftera period as Licensing Manager. As a VicePresident of sales and marketing, he now hasoverall responsibility for the oxo business.

Mike Ashley spent many years with JohnBrown, involved with process technology andbusiness development, before joining DavyProcess Technology. He is now concernedwith business analysis, technologyacquisition, marketing, website developmentand all aspects of public relations.

References

LP OxoSM and SELECTORSM are service marks of The DowChemical Company.

NORMAXTM is a trademark of The Dow Chemical Company.


The second Novel Chiral Chemistries Japan(NCCJ) Conference and Exhibition was held inTokyo from 16th to 17th April, 2007. The firstmeeting in the series had been held in 2006 and asimilar format was followed. There were threekeynote addresses with supporting lectures.Professor Takao Ikariya (Tokyo Institute ofTechnology) did an excellent job as the confer-ence organiser. During the coffee and lunchbreaks there was a small exhibition by companiesassociated with chiral chemistry. The exhibitorsranged from companies that provide biocatalysts,metal catalysts and ligands through to serviceproviders associated with the implementa-tion of methodologies. Some scientific instru-mentation was also on display. There were about100 delegates, most coming from the Japanesefine chemicals industry.

Keynote PresentationsThere were three keynote addresses. The first

was by Professor Henri Kagan (University Paris-Sud, France) who described some of the generalproblems associated with finding a catalyst for aspecific purpose when non-linear effects areobserved. This was highlighted by examples ofasymmetric depletion, when a low degree ofasymmetric induction can occur unless the cata-lyst has an extremely high enantiopurity.

The second keynote address was presented byProfessor Gregory Fu (Massachusetts Institute ofTechnology, U.S.A.). This lecture covered thedevelopment of chiral nucleophilic catalysts basedon 4-aminopyridines bound to ferrocene deriva-tives. These catalysts have proved useful for theasymmetric conversion of ketenes to α-substitut-ed esters. In the presence of copper, the ferrocenederivatives can be used to prepare α-alkoxy esters.This chemistry has led to the development of chi-ral azaferrocenes for the asymmetric formation ofcyclopropanes from diazocompounds.

The third and final keynote address was byProfessor Tsuneo Imamoto (Chiba University,Japan) who described how his work had progressedfrom BisP*, 1, and MiniPhos, 2, to other ligandsbased on the concept of P-chirality, as originallyimplemented by Knowles with DIPAMP (1).

The synthesis of both ligand series involvesorganometallic chemistry, with the phosphorus sta-bilised as a borane adduct for asymmetricdeprotonations with sec-butyllithium in the presenceof sparteine. The rhodium complexes of these lig-ands provide high enantioselectivity in the reductionof dehydroamino acid derivatives, enol esters andenamides. Hydrosilylation of ketones providesaccess to chiral secondary alcohols. The iridiumcomplexes of these ligands can be used to reduceimines to amines, again with high stereoselectivity.This work is now being extended to AlkynylP*,where the methyl group of BisP* has been replacedby alkynyl groups. These ligands have shown highselectivity for the addition of arylboronic acids toenones. This latter reaction can also be performedwith QuinoxP*, 3, which also provides high asym-metric induction in the rhodium-catalysed reductionof enamides and palladium-catalysed addition ofdialkylzinc to 7-oxabicyclohepta[2.2.1]dienes.

Novel Chiral Chemistries Japan 2007Reviewed by David J. AgerDSM, PMB 150, 9650 Strickland Road, Suite 103, Raleigh, NC 27615, U.S.A.; E-mail: [email protected]

DOI: 10.1595/147106707X233928

PPR

R

BisP*

PP

R

R

BisP* MiniPhosR = alkyl substituent

1 2

N

N P

PR

R

QuinoxP*3R = alkyl substituent


Asymmetric CatalysisIn addition to these keynote addresses, there

were fifteen other presentations. The topicsranged from the use of biocatalysts and chiralauxiliaries through to the design of ligands andapplications of both approaches in pharma-ceutical case studies. Only the talks relating to theuse of platinum group metals (pgms) have beensummarised here, in line with the emphasis ofthis publication.

Rocco Paciello (BASF, Germany) describedhow the phosphanylpyridones designed byProfessor Bernhard Breit from the University ofFreiburg, Germany, can be used in hydroformyl-ation reactions of terminal alkenes in the presenceof rhodium, to provide high selectivity for theformation of aldehydes. Asymmetric reactionswere illustrated by hydrogenations where phos-phonites from the Breit collaboration areavailable. Catalyst screening was the topic of anumber of the presentations, and the BASFapproach was illustrated by a synthesis of(R)-2-methylpentanol where the successful ligandfor the rhodium-catalysed reduction of the allylalcohol precursor was SolPhos, 4. For the reduc-tion of itaconic esters, rhodium with RoPhos, 5,was found to be the successful combination.

For the reduction of ketones, transfer hydro-genation is the preferred method of operationand this is being scaled up using a continuousprocess. In addition, the presence of a smallamount of carbon monoxide has been found tobe advantageous.

Antonio Zanotti-Gerosa (Johnson Matthey,U.K.) described work that has been done byJohnson Matthey, in collaboration with the Royal

Institution and the Universities of Liverpool andSouthampton, U.K., on computational invest-igation into ketone reduction with the ruthenium-BINAP-DPEN system. There seem to besignificant differences in performance betweenthe XylBINAP and TolBINAP systems. Thiscould be due to the way in which the substratedocks with the metal catalyst (2).

Hideo Shimizu (Takasago International Corp.,Japan) described work on the direct reduction ofenamines to β-amino esters with DM-SegPhos, 6.The second part of the talk was on new workrelated to the reduction of aryl ketones by the useof copper catalysts with BDPP, 7, (also known asSkewPhos) as the chiral ligand.

Professor Hisao Nishiyama (NagoyaUniversity, Japan) described his work withRh(Phebox), 8, for the conjugate reductions ofα,β-unsaturated esters, enals and enones. As anenolate is formed in the reaction, the intermediatecan be reacted with an electrophile to performaldol and other reactions. This approach gives arapid and powerful approach to chiral 3-hydroxy-2-alkyl esters.

Hans-Jürgen Federsel (AstraZeneca, Sweden)gave a number of examples of differentapproaches for the preparation of chiral pharma-ceutical compounds. For the synthesis of acomplex 2-aminotetralin, the nitrogen at the

N

O

O

N

PPh2

PPh2

SolPhos

P

P

OH

OH

OH

OH

SolPhos RoPhos4 5

O

O

O

O

P(3,5-xyl)2

P(3,5-xyl)2

DM-SegPhosDM-SegPhos

PPh2 PPh2

6 7 BDPP (SkewPhos)

O

N N

O

i-Pr Pr-i

Rh

OH2

OAc

AcO

Rh(PheBox)(OAc)2(H2O)Rh(ip-Phebox)(OAc)2(H2O)8


stereogenic centre was introduced by a reductiveamination with phenylethylamine. The Buchwald-Hartwig approach with palladium acetate in thepresence of BINAP afforded the piperazine cou-pled product (Scheme I).

Professor Jaiwook Park (Pohang University ofScience and Technology, South Korea) describedhis work on the dynamic kinetic resolution ofamines through the use of enzymes to stereo-specifically prepare an amide from racemic amine.A metal catalyst provides the ability for an in siturecycling of the amine enantiomer that is not asubstrate for the enzyme. The metal catalyst isbased on palladium nanoparticles entrapped inaluminium hydroxide, prepared by heatingaluminium tri-sec-butoxide and tetrakis(tri-phenylphosphine)palladium in butanol in air.

The theme of a dynamic kinetic resolutionwas continued by Renat Kadyrov (DegussaHomogeneous Catalysts, Germany), whodescribed how the use of Rh(Norphos), 9, couldbe employed for the reduction of racemicN,O-acetals, aminols, to prepare chiral amines, as1,2-amino alcohols. Other reductive approaches

to chiral amines include the use of catASium® D,10, to prepare α-amino acids from α-keto acidsand a transfer hydrogen method with rutheniumTolBINAP for ketones.

Makoto Itagaki (Sumitomo Chemical Co., Ltd.,Japan) described the development of catalysts forthe asymmetric synthesis of cyclopropanes. Inaddition to control of enantioselectivity, thecis:trans ratio has to be controlled. The productsare used in the agricultural industry and may beapplied as a mixture, but there is still a need toproduce the active isomer in the most cost-efficient manner available. The development ofcatalysts for the addition of the diazoesters toalkene has led to the copper-pybox analogue 11.

David Ager (DSM, U.S.A.) described themethods employed to find the best catalyst for an

Br

O

H2N

TsOH

Br

N

1. NaBH4, MeOH, IPA

2. HCl, EtOAc

Br

NH

NHN

Pd(OAc)2, BINAP,NaOBu-t, toluene

N

NH

55%92% de

N95%

1. H2, PdÐC, H2O, AcOH

2. PhCO2H, toluene N

NH2

N

¥HO2CPh

88%

H2, Pd/C, H2O, AcOH• H

NaOtBu, toluene

Scheme I Synthesis of a complex 2-aminotetralin (de = diastereomeric excess)

PPh2

PPh2

NorPhos

N Bn

Ph2P

Ph2P

catASium DNorPhos catASium® D

(Bn = benzyl)9 10


asymmetric transformation. The ligand system is amonodentate phosphoramidite and those basedon BINOL are known as the MonoPhosTM, 12,family. These ligands can provide excellent asym-metric induction for the reduction in the presenceof rhodium of a wide range of carbon–carbondouble bonds (3). The ligands are now provinguseful in the rhodium-catalysed additions of aryl-boronic acids to aldehydes and imines.

Yongkui Sun (Merck & Co., U.S.A.) describedhow screening is a powerful tool to find asymmet-ric catalysts in the pharmaceutical industry. Threecase studies were presented. The first involved adynamic kinetic resolution approach for thereduction of a ketone to alcohol with control ofthe α-stereocentre to produce the desired isomer.The method used a Noyori approach. The synthe-sis also involved the conversion of an arylbromide to nitrile with Pd(o-Tol)4 and zinccyanide. In the second example, the target mole-cule was the same, but Rh(TMBTP), 13, was usedto reduce an enamide. For this approach, theenamide was prepared by a palladium-catalysedcoupling of a vinyl tosylate with an amide. Thethird example was for the synthesis of sitagliptin,where a Ru(BINAP) reduction of an unsaturated

acid provides the desired isomer as isomerisationof the substrate occurs under the conditionsemployed for the reduction.

Concluding RemarksAs with the first meeting, NCCJ 2007 was held

in the same week as CPhI Japan (4). The meetingallows interactions between Japanese companiesand academics with their counterparts fromEurope and the U.S. In addition to new method-ologies, application of methods and the problemsassociated with implementation in industrial set-tings provide a background emphasising the needto develop both more efficient catalysts and themeans to identify them.

The wide variety of topics and applications dis-cussed demonstrates that use of the pgmscontinues to provide new and useful methodolo-gies to prepare molecules on an industrial scale. Ihope this excellent series continues to grow andprosper.

References1 W. S. Knowles and M. J. Sabacky, Chem. Commun.

(London), 1968, 14452 S. A. French, Platinum Metals Rev., 2007, 51, (2), 543 D. J. Ager, A. H. M. de Vries and J. G. de Vries,

Platinum Metals Rev., 2006, 50, (2), 544 CPhI Japan: http://www.cphijapan.com/eng/

NCu

N

O O

PF6

R1R2

R2 R1

O

OP N

R4

R3

MonoPhos family

S

S

PPh2

PPh2

TMBTP

11

MonoPhosTM family

TMBTP

Cu-pybox analogue

12

13

The ReviewerDavid Ager has a Ph.D. (University ofCambridge), and was a post-doctoral workerat the University of Southampton. Heworked at Liverpool and Toledo (U.S.A.)universities; NutraSweet Company’sresearch and development group (as aMonsanto Fellow), NSC Technologies, andGreat Lakes Fine Chemicals (as a Fellow)responsible for developing new synthetic

methodology. David was then a consultant on chiral and processchemistry. In 2002 he joined DSM as the Competence Managerfor homogeneous catalysis. In January 2006 he became aPrincipal Scientist.

Organometallic catalysis has been based foryears on phosphine and cyclopentadienyl ligands.These stood alone as the leading ligand classesbecause they were sterically and electronically tunable to achieve desired levels of catalyst selectivity and activity. In the case of the phosphine series, such tuning was particularly easyusing the Tolman ‘map’ that predicted the stericand electronic effects of almost any phosphine orrelated phosphorus donor ligand (1, 2).

N-Heterocyclic carbenes (NHCs), 1, are ligandsformed by the deprotonation of an N,N′-disubsti-tuted imidazolium (or other azolium) salt. Bindingof a transition metal to the C2 carbon of the NHCleads to the formation of a very strong metal–carbon bond, the strength deriving from the ther-modynamic instability of the free NHC. Unlikemetal–carbon bonds in general, those to NHCs donot undergo fast insertion or reductive eliminationreactions and so NHCs are relatively reliable spec-tator ligands. The role of a spectator ligand is toact as a placeholder by promoting a desired reac-tion at the metal, while avoiding dissociation orentering directly into the reaction. NHCs are sig-nificant in being the first new series of spectatorligands in several decades to rise to prominence,having both steric and electronic tunability andthe capability to promote catalysis of many usefulcatalytic reactions.

Early work in the 1960s and 1970s laid out thebasis of the field but the full potential of these lig-ands was not fully realised at that time. Only with

work from the 1990s and specially since 2000 havethese ligands achieved major prominence. Perhapsthe most dramatic example of their utility was thediscovery by Grubbs and coworkers (3) that NHCligands could greatly improve the performance ofthe Grubbs ruthenium metathesis catalyst.

A recent special issue of Coordination ChemistryReviews, with guest editor Robert H. Crabtree, hasnow been devoted to the NHC ligands (4). Amongseveral notable reviews, Ivan Lin and ChandraVasam address Lin’s metallation procedure for thesynthesis of NHC complexes. The procedure isimportant in that it avoids strong base and insteaduses Ag2O to metallate the usual N,N′-disubstitut-ed imidazolium NHC precursor salt. This is nowone of the most popular methods of introducingNHCs into metal complexes, because the silverNHC complexes initially formed readily transmet-allate to other metals, such as palladium orrhodium.

Polly Arnold and Stephen Pearson describe thechemistry of abnormal NHCs, in which a metal isbound not at the usual C2 carbon but at C4(5).These are much stronger electron donors, butsomewhat more easily cleaved from the metalcompared with their normal NHC analogues.

Andreas Danopoulos and David Pugh treat‘pincer’ versions of NHCs, a ligand type that hasbeen very fruitful in terms of catalytic complexes,both in the NHC and in the phosphine series.

N-Heterocyclic Carbenes inCatalysis and Biomedicine

Lutz Gade and Stéphane Bellemin-Laponnaz’sreview deals with oxazoline-modified NHCs inrelation to asymmetric catalysis. Steven Diver dis-cusses recent advances in enyne metathesis withNHC ruthenium complexes. Asymmetric catalysis


“Recent Developments in theOrganometallic Chemistry ofN-Heterocyclic Carbenes”GUEST EDITOR: ROBERT H. CRABTREE (Yale University, U.S.A.), Coordination Chemistry Reviews, 2007,Special Issue, Volume 251, Issues 5–6, pp. 595–896

DOI: 10.1595/147106707X231560

RN NR

• •NHC1 N-Heterocyclic carbene (NHC)

RN NR


continues to be of intense interest and many asym-metric NHCs have been developed. For example,Richard Douthwaite discusses palladium-mediatedasymmetric alkylation using chiral NHCs derivedfrom chiral amines.

Frédéric Lamaty et al. review the NHC-modi-fied Grubbs catalysts. Valerian Dragutan andcoworkers review other aspects of rutheniumNHC catalysis. Miguel Esteruelas et al. look at arelated element, osmium, and its carbene chem-istry. Eduardo Peris and coworkers review someligands with NHCs in bidentate and tripod config-urations, together with their catalytic properties.Marcus Weck and William Sommer cover support-ed catalysis involving NHC ligands withruthenium and palladium.

In connection with the problem of pre-dicting the stereoelectronic properties of NHCs,Steve Nolan and Silvia Díez-González discusstheir development of a set of reliable stereoelec-tronic parameters for NHC ligands with a view tounderstanding how stereoelectronic effects con-trol metal-catalysed reactions.

Wiley Youngs and coworkers go far beyondcatalysis into the biomedical area. They show thatsilver NHC complexes can have useful anti-

microbial activity. Encapsulation in a polymer matallows sustained delivery of silver ions, useful inwound care. Numerous resistant respiratorypathogens in cystic fibrosis are sensitive to a caf-feine-derived silver-NHC complex.

Concluding RemarksThis field holds much promise for future devel-

opment because of the very large range ofpossibilities opened up by the availability of a vastrange of azole structures of various sorts. We canexpect other azoles, such as triazole and thiazolederivatives, for example, as well as a large array ofdifferent chelate arrangements and mixed ligandsystems. For catalytic applications, NHCs havebeen chiefly incorporated into platinum groupmetals, but they prove to have a much wider affin-ity for d-block, f-block and main group elementsthan do phosphines or cyclopentadienyls, so theirultimate potential is vast.

The Guest Editor of the ReviewBob Crabtree, educated at New College, Oxford, U.K. with MalcolmGreen, did his Ph.D. research with Joseph Chatt at Sussex and thenspent four years in Paris with Hugh Felkin at the Centre National de laRecherche Scientifique (CNRS). He has been at Yale University since1977, where he is now Professor. He has received several awards: A. P.Sloan Fellow, Dreyfus Teacher-Scholar, American Chemical Society (ACS)and Royal Society of Chemistry organometallic chemistry prizes, H. C.Brown Lecturer, Mack Award, Baylor Medal and Sabatier Lecturer. He haschaired the Inorganic Division at the ACS. He is the author of a textbook

in the organometallic field, and editor-in-chief of the “Encyclopedia of Inorganic Chemistry” and“Comprehensive Organometallic Chemistry”. Early research on catalytic alkane C–H activationand functionalisation chemistry was followed by work on C–F bond activation, H2 complexes,M–H…H–O hydrogen bonding, and molecular recognition in C–H activation. His homogeneoushydrogenation catalyst is in wide use.

References1 C. A. Tolman, J. Am. Chem. Soc., 1970, 92, (10), 29532 C. A. Tolman, Chem. Rev., 1977, 77, (3), 3133 T. M. Trnka and R. H. Grubbs, Acc. Chem. Res., 2001,

34, (1), 184 Coord. Chem. Rev., 2007, 251, (5–6), 595–896

178

There has been much recent interest in the tech-nical literature in the rheological features ofplatinum alloys for jewellery applications (1, 2). Bycontrast, in industrial applications, platinum is oftenused in the form of the nominally pure metal, sinceimpurities and alloying elements can adversely affectits working characteristics (3, 4). 99.93 wt.% pureplatinum is used in Russia, for instance, to produceheat- and chemical-resistant crucibles.

To comply with the Russian State StandardGOST 13498-79 (5), platinum must be at least 99.93wt.% pure (i.e. the overall total impurity content isnot more than 0.07 wt.%). Palladium, rhodium, irid-ium and ruthenium impurities must not exceed 0.04wt.% in total, and the upper limits (in wt.%) forother impurities are as follows: silicon 0.005, iron0.01, gold 0.008 and lead 0.006. It should be notedthat unlike alloys, the mechanical characteristics ofpure metals depend strongly on their impurity con-tent, which must be determined experimentally.

99.917 wt.% pure platinum test samples wereprepared for the present work. Impurity levels (inwt.%) were analysed as follows: Pd 0.06, Rh 0.01, Ir0.007, Si 0.001, Fe 0.003, Au 0.001 and Pb 0.001.The chemical composition of the platinum testsamples was therefore close to that required byGOST 13498-79.

The test blanks for the current work wereobtained by means of cast moulding a platinum bar50 mm thick and hot forging at 900 to 1530ºC, withsubsequent cold rolling of the sheet material. Thethicknesses of sheets obtained by rolling of the 25mm forged blanks were 1.25, 0.83, 0.71, 0.63 and0.56 mm. The forged blanks underwent annealing ina batch furnace at a temperature of 1000ºC for 40minutes, so as to achieve recrystallisation. This tem-perature was initially assumed to be high enough toensure complete recrystallisation (2). Using such ahigh annealing temperature industrially is controver-sial, since it can adversely affect the structure of themetal and some of its working characteristics.

In determining the force/energy parameters forprocesses involving pressure working, the strainresistance, σs, is understood to be a function of thestrain state of the sample, in terms of compressionand degree of strain (6). The deformation resistanceis considered in terms of the uniaxial compressionor tension of the sample under conditions of plasticdeformation. It was assumed that during cold defor-mation, the deformation resistance depends only onthe geometric parameters of the change in shape.

In order to plot hardening curves as a functionof deformation, starting at zero, the original materi-al must be fully recrystallised. To establish the

Platinum Metals Rev., 2007, 51, (4), 178–184

Annealing Characteristics and StrainResistance of 99.93 wt.% PlatinumIMPLICATIONS FOR THE MANUFACTURE OF PLATINUM ARTEFACTS

By Yu. N. Loginov*Ural State Technical University, Metallurgical Department, 19 Mira Street, 620002 Ekaterinburg, Russia; *E-mail: [email protected]

and A. V. Yermakov**, L. G. Grohovskaya and G. I. StudenokThe Ekaterinburg Non-Ferrous Metals Processing Plant JSC, 8 Lenin Avenue, 620014 Ekaterinburg, Russia;

**E-mail: [email protected]

In industrial applications, platinum is often used in the form of the nominally pure metal, sinceimpurities and alloying elements may adversely affect both its working characteristics and itsstability against corrosion, at both ambient and high temperatures. Low strength, typical ofa metal of this purity, is accepted in industrial products despite being a significant disadvantage.To optimise the technical parameters for the thermal and mechanical processing of platinum,knowledge is required of its rheological characteristics, including deformation resistance.

DOI: 10.1595/147106707X237708


transition temperature for recrystallisation, experi-ments were set up to determine the yield limit as afunction of the annealing temperature. An initialshear strain Λ was determined by varying the com-pression ε% of the blanks during cold sheet rolling(i.e. in the flat deformed condition), and calculatedby Equation (i):

Λ = 2ln(h0/h1) (i)

where h0 and h1 are the sample thicknesses beforeand after rolling, respectively. We also defined:

ε% = 100Δh/h0 (ii)

where Δh = h0 – h1.Using the generalised deformation characteristic

Λ allows for summation as the deformation accu-mulates. This approach is also compatible with themajority of computer programs for calculatingstress-strain characteristics.

The prepared platinum strips were rolled to afinal thickness of 0.5 mm on a mill with 300 mmdiameter rollers, imparting them with varyingdegrees of cold working. Flat ten-fold samples werethen cut from the sheets, with their long axes ori-ented along the rolling axis. The samples were thenannealed at temperatures from 200 to 1100ºC.

Tension tests were conducted on an “Instron 1195”machine, using a traverse speed of 1 mm min–1, andthe Vickers hardness HV5 was measured. Hardnessis plotted against annealing temperature in Figure 1,the legend for which is given in Table I.

Results of Hardness TestingThe experimental results showed that the

Vickers hardness of platinum can vary very con-siderably within the wide range 500–1500 MPa,depending upon the degree of strain. It should benoted that standard references (e.g. (7)) give theVickers hardness of platinum of technical purity, inthe annealed state, in the range 350–420 MPa; cal-culation from the HV value in Reference (8) gives

0 200 400 600 800 1000 1200

Fig. 1 Experimentalschematic and results formeasurement ofdependence of Vickershardness, HV5, for99.93 wt.% platinum onannealing temperature, t0,and initial degree of shearstrain, Λ (averaged data).See Table I for legend

Table I

Legend for Figure 1

Symbol Λ (averaged data) h0, mm h1, mm

0.15 0.560 0.5200.40 0.630 0.5150.68 0.710 0.505

× 0.97 0.830 0.510* 1.91 1.250 0.480

7.78 25.000 0.505


392 MPa. This spread of values is explained by thevarying chemical composition of the platinum sam-ples tested; in the present work, the platinumcontained 0.01 wt.% rhodium as the principalstrengthening element.

Figure 1 shows that full annealing is reached onheating to 400ºC if the metal is cold-worked to thehigh degree of shear strain of 7.78 (compressionε% = 97.96%). With decreasing initial deformation,the annealing point shifts towards higher tempera-tures. Thus, with a degree of initial sheardeformation greater than 0.4 (compression 18%),the annealed state is reached at temperatures above700–800ºC. At lower degrees of compression, themetal can be softened only by heating to above1000ºC.

Figure 2 shows the dependence of the annealingtemperature t0 of platinum on initial shear strain.Regression analysis gives Equation (iii) for thisdependence, with a correlation coefficient of 0.982:

t0 = 695 – 141 ln(Λ) (iii)

Minimising the annealing temperature on thebasis of the degree of deformation in the metal istechnologically significant, since at higher annealingtemperatures, collective recrystallisation occurs andgrain size increases, and the plastic characteristicsare adversely affected. The decrease in recrystallisa-tion temperature with increasing shear strain maybe explained in terms of an accumulation of inter-nal energy in the crystal lattice during cold working.

This stored energy derives from heating during theannealing process. As a result, the annealing tem-perature may be lower for hardened than forunhardened metal.

Deformation ResistanceThe sheet material used for the present experi-

ments was prepared by repeated rolling of flatplatinum samples. The results of tension tests pro-vided values of yield strength corresponding touniaxial tension, and hence the deformation resis-tance σs.

There are two principal methods for determin-ing deformation resistance. In the first, flatspecimens are rolled on a mill to a range of thick-nesses. The specimens are then subjected touniaxial tension tests, so as to determine the con-ventional yield strength. This is an empiricalparameter, defined in terms of the stress which willproduce a given degree of conventional strain. σ0.2

is defined as the stress to produce 0.2% conven-tional strain. It is usually assumed that σs = σ0.2,since both parameters refer to the start of plasticdeformation. The advantage of this method is thatno neck is formed, and high degrees of plasticdeformation are therefore attainable.

The second method is uniaxial tension testing,during which true (not conventional) stress anddeformation are measured. Plots of σs vs. either ε%

or Λ are obtained. A disadvantage of this method isthat a neck is formed, and large deformations can-

0 1 2 3 4 5 6 7 8

Λ

Fig. 2 Influence of initialshear strain, Λ, onannealing temperature, t0,of 99.93 wt.% platinum


not be achieved. In this work, σ0.2 is taken as a mea-sure of the stress at which plastic deformationbegins under uniaxial tension. σs is adopted forstress-strain calculations in which the stress condi-tion is not one of uniaxial tension. Experimentalmeasurements have provided results for σ0.2 as afunction of the degree of preliminary hardening.

Different researchers employ a variety of factorsin evaluating metal hardening. Here, we considerdeformation in terms of: the shear deformation, Λ,given by Equation (i):

Λ = 2ln(h0/h1) (i)

and the relative compression ε%, given by Equation(ii):

ε% = 100Δh/h0 (ii)

In order to plot hardening curves for metals inthe cold state, it is important, where possible, tomeasure accurately the nominal yield strength of themetal in the unhardened state.

Experiments in processing semi-finished plat-inum products showed that the conventional yieldstrength of the material is rather variable, by con-trast with its tensile strength. Plots of thedependence of σ0.2 on the initial shear deformationand the annealing point (Figure 3) showed that

GOST 13498-79 grade platinum may have a yieldstrength anywhere in the range 50 to 230 MPa,depending on its thermomechanical processing his-tory. The yield strength decreases with increasingannealing temperature.

It was found that, at lower annealing points (600to 700ºC), the dependence of σ0.2 on Λ shows amaximum in the range Λ = 0.8 to 1.5, correspond-ing to ε% = 30 to 50%. At higher temperatures, σ0.2

decreases monotonically with increasing Λ. Atannealing points in excess of 1000ºC, the prior coldworking of the metal ceases to have an effect. Undersoftening conditions, σ0.2 takes a characteristic valueof 60 MPa, and this was treated as a constant in theregression equations.

The experimental results may be explained asfollows. At low annealing temperatures, σ0.2 increas-es with increasing Λ, because the metal has beensubjected to hardening by cold rolling. Under theseconditions, annealing has little softening influence.However, if Λ rises to between 0.8 and 1.5, anneal-ing has sufficient influence to soften the metal. σ0.2

therefore decreases again, and the curve shows amaximum. If the annealing temperature is over800ºC, the curves show no maxima, because theinfluence of annealing is sufficient for full softening,without taking into account the energy of plastic

Fig. 3 Experimental schematic and results for measurement of dependence of conventional yield strength, σ0.2, for99.93 wt.% platinum, on initial degree of shear strain, Λ, and annealing temperature, t0: 600ºC; 700ºC; * 800ºC;× 900ºC; 1000ºC; 1100ºC


deformation.The practical significance of this observation lies

in the possibility of choosing annealing regimes toobtain the desired metal characteristics. For exam-ple, in some industrial applications, pure platinum isused as a fabrication material, in spite of the lowstrength of products made from it. Improved prod-ucts with greater strength, desirable for vessels andcrucibles, may be achieved through plastic deforma-tion and partial annealing.

Effect of Annealing Temperature onGrain Size

Higher annealing temperatures increase grainsize. This effect is particularly evident at tempera-tures over 900ºC, where it is attributable tocollective recrystallisation (Figure 4). A fine crystalstructure is preferred for the deep forming of vessels and crucibles.

The dependence of conventional yield strengthon shear deformation for Pt 99.93 is shown in

Figure 5, which indicates that the deformation resis-tance of the metal may vary between 60 and 460MPa. Depending on the case selected, linear regres-sion analysis gave Equations (iv)–(vi) for thehardening curve:

σs = 60 + 214Λ0.334 (iv)

σs = 60 + 269ε0.334 (v)

σs = 60 + 39.8ε%0.481 (vi)

The amount of strain, ε, is given by ε = ln(h0/h1).The correlation coefficient of regression forEquations (iv) and (v) is 0.9873, and for Equation(vi), 0.9726. These values indicate that the approxi-mations are satisfactory. Determining the exponentin Equation (iv) enables the degree of deformationin platinum under draw-forming to be predicted. Inaccordance with plasticity theory, the sheet retainsits shape without necking, if the exponents inEquations (iv) or (v) are high enough.

Stress-Strain AnalysisStress-strain conditions during the deformation

of platinum crucibles have been calculated by finite-element methods (9). Figure 6 shows the results fordeep drawing of a product of thickness S, using adie of radius rm. The shear deformation Λ shows anon-uniform distribution, with its maximum at thepunch radius. There are two shear deformationmaxima along the radius of the sample, which cor-respond to the two hardening maxima.

These investigations of annealing regimes andhardening conditions have practical implications forthe production of platinum vessels at the

(a) (b)

Fig. 4 Structure of 99.93 wt.% platinum (× 100) aftercold rolling at Λ = 1.91 (h0 = 1.250 mm, h1 = 0.480 mm)and annealing for 40 minutes at: (a) 800ºC; and(b) 1000ºC

Fig. 5 Dependence ofdeformation resistance, σs,on shear strain, Λ, for99.93% platinum


Ekaterinburg Non-Ferrous Metals Processing Plant,Russia. The plant produces chemically stable plat-inum crucibles in a range of shapes (see Table II). Aselection is shown in Figure 7.

ConclusionsThe annealing temperature range for 99.93 wt.%

platinum is 400–1000ºC, and depends on thedegree of cold working. Annealing is possible at

400ºC if the shear strain Λ is at least 7.78, or the rel-ative compression ε% is at least 97.96%.

Annealing at temperatures higher than 900ºCincreases grain size; this is attributable to collectiverecrystallisation. Depending on the strain condi-tion, the preferred annealing temperature range istherefore 400 to 800ºC.

The conventional yield strength σ0.2 dependsnon-linearly on the degree of shear deformation.This has been analysed in terms of hardening by aregression analysis.

At low annealing temperatures, σ0.2 increaseswith increasing Λ, because the metal has been sub-jected to hardening by a cold rolling process.However, if Λ rises to between 0.8 and 1.5, anneal-ing is sufficiently powerful to soften the metal. σ0.2

therefore decreases, and the curve shows a maxi-mum.

The strain resistance of 99.93 wt.% platinumranges from 60 to 460 MPa as Λ increases from0 to 7.78.

The data obtained in the present work allowstress-strain relations to be calculated as a functionof deformation for semi-finished platinumartefacts.

Table II

Dimensions of Some of the Shapes of PlatinumCrucible Produced by Ekaterinburg Non-FerrousMetals Processing Plant, Russia

Diameter, mm Height, mm

8 8.528 2238 12842 30

135 150

Fig. 6 Detail of stress-strain calculation for deepdrawing of platinum at rm/S = 8

Fig. 7 Chemically stable platinum crucibles. (The red coloration is a reflection of the background.)

References1 J. C. Wright, Platinum Metals Rev., 2002, 46, (2), 662 T. Biggs, S. S. Taylor and E. van der Lingen, Platinum

Metals Rev., 2005, 49, (1), 23 K. Toyoda, T. Miyamoto, T. Tanihira and H. Sato,

Pilot Pen Co Ltd, ‘High Purity Platinum and ItsProduction’, Japanese Patent 7/150,271; 1995

4 K. Toyoda and T. Tanihira, Pilot Pen Co Ltd, ‘HighPurity Platinum Alloy’, Japanese Patent 8/311,583;1996

5 Russian State Standard GOST 13498-79, ‘Platinumand Platinum Alloys.’ ‘Trade Marks’, Moscow, 1979


The Authors

6 E. P. Unskov, W. Johnson, V. L. Kolmogorov, E. A.Popov, Yu. S. Safarov, R. D. Venter, H. Kudo, K.Osakada, H. L. D. Pugh and R. S. Sowerby, “Theoryof Plastic Deformations of Metals”, Mashinostroenie,Moscow, 1983 (in Russian)

7 “Precious Metals Handbook”, ed. E. M. Savitsky,Metallurgiya, Moscow, 1984, (in Russian)

8 Properties of Platinum Group Metals: PlatinumToday, Johnson Matthey: http://www.platinum.matthey.com/applications/properties.html

9 Yu. N. Loginov, B. I. Camenetzky and G. I.Studenok, Izvestiya Vysshikh Uchebnykh Zavedenii,Chernaya Metallurgiya, 2006, (3), 26

Yuri N. Loginov, Dr.Sc. (Techn.) is theProfessor in the Metallurgical Department ofthe Ural State Technical University, where hedirects work on the plastic deformation ofnonferrous metals. He is the author of fourmonographs, 40 university-level textbooks,300 scientific publications and 120 patents.

Alexander V. Yermakov, Cand.Sc. (Phys. &Math.), is a Senior Researcher and the DeputyDirector of the Ekaterinburg Non-FerrousMetals Processing Plant. He is the author ofmonographs and over 150 scientificpublications and patents. His interests lie in thestudy of the properties of noble metals andtheir alloys, and creation of industrialtechnology for their fabrication.

Lilia G. Grohovskaya is a supervisor in theresearch laboratory section of theEkaterinburg Non-Ferrous Metals ProcessingPlant. She has wide experience in noblemetals research.

Gennadi I. Studenok, an engineer in thescientific laboratory of the Ekaterinburg Non-Ferrous Metals Processing Plant, is a Ph.D.student in the Metallurgical Department of theUral State Technical University, researching themechanics of deformation processes in noblemetals.

The conference was held in Weimar, Germany,from 14th to 16th March 2007 (1). It was the 40thanniversary of this annual meeting, which wasfounded in 1967 in eastern Germany. The confer-ence attracted more than 450 visitors fromindustry and academia, mainly from Germany.Forty lectures in two parallel sessions were pre-sented, and there were more than 200 postercontributions. Of the six plenary lectures, fourwere given by international speakers. This selectivereview covers aspects of the presented workfeaturing the platinum group metals (pgms).

LecturesJ.-M. Basset (École Supérieure Chimie Physique

Électronique de Lyon, France) described in his plenary lecture: ‘Catalysis: From Molecules toMaterials’, the progress of molecular andsupramolecular chemistry for the rational design ofcatalysts. With numerous examples, such as for thepgm-catalysed metathesis of olefins, he gave illus-trations of new developments.

In a lecture entitled ‘New Thermally StableCatalysts via Encapsulation of Metal Nanoparticlesin MeOx Empty Spheres’, M. Paul, M. Comotti, P. Arnal, P. Bazula and F. Schüth (Max-Planck-Institut für Kohlenforschung, Mülheim an derRuhr, Germany) outlined an elegant synthesis ofmetal particles such as gold nanoparticles in a ZrO2

hollow sphere. The Au nanoparticles are coveredby SiO2, which is then coated with ZrO2. The SiO2

can be removed chemically. The remaining ZrO2

with encapsulated Au is thermally stable, and theAu particles are protected from sintering. Themethod can also be used for other precious metalssuch as platinum and palladium.

M. Beller (Leibniz-Institut für Katalyse e.V.,Universität Rostock, Germany) gave a lecture on‘Homogeneous Catalysis – A Key Technology forthe 21st Century’. As examples of topics success-

fully addressed, in terms of both fundamentalresearch and technical application, Beller cited Pd-catalysed C–C coupling reactions and atom-efficient carbonylations.

Poster ContributionsG. Incera Garrido, F. C. Patcas, G. Upper,

M. Türk and B. Kraushaar-Czarnetzki (UniversitätKarlsruhe, Germany), presented a poster entitled:‘Preparation of Pt/SnO2 Supported Catalysts forthe CO-Oxidation: Comparison between Classicaland Supercritical Pt Deposition’. The catalyst, pre-pared via supercritical carbon dioxide (scCO2)deposition of Pt, oxidised CO at 80ºC withremarkable activity, whereas the catalyst made viaconventional aqueous preparation shows no activ-ity below 150ºC.

S. Kureti and F. J. P Schott (UniversitätKarlsruhe) presented a poster about ‘Reduction ofNOx by H2 on Pt Containing Catalysts in DieselExhaust’. The preferred techniques to meet emis-sion standards are NOx storage catalyst (NSR) andselective catalytic reduction (SCR), using NH3 asreductant. However, a serious constraint on thesetechnologies is that efficient NOx conversion isonly achieved above 150ºC. The EuropeanCommission Motor Vehicle Emissions Group(MVEG) (2) estimates that the exhaust tempera-ture of diesel passenger cars is below 150ºC forabout 60% of the time, indicating a need for atechnique to convert NOx in the low temperaturerange. The reduction of NOx by H2 on Pt catalystsis considered to be a promising method. However,it is well known that the H2/NOx reaction on clas-sical Pt/Al2O3 gives N2O. To obtain selectiveproduction of N2, the catalyst was modified. Thebest catalyst so far gave 80% selectivity to N2.

A. Boonyanuwat, A. Jentys and J. A. Lercher(Technische Universität München, Germany)reported on: ‘Hydrogen Production by Aqueous-


40th Conference ‘Deutscher Katalytiker’PLATINUM GROUP METALS AT THE GERMAN CATALYSIS CONFERENCE

Reviewed by Thomas IlkenhansJohnson Matthey Technology Centre, Blounts Court, Sonning Common, Reading RG4 9NH, U.K.; E-mail: [email protected]

DOI: 10.1595/147106707X234800


Phase Reforming of Glycerol on Supported MetalCatalysts’. Platinum and palladium on aluminashow the best selectivities to hydrogen (greaterthan 90%), while rhodium also gave alkane selec-tivity. A stability test was carried out for two weeksat 498 K and 29 bars. During this time, the activi-ty of the catalysts was almost constant.

Concluding RemarksIn summary, the meeting in Weimar, the beau-

tiful city of Goethe and Schiller, covered thewhole range of heterogeneous and homogeneouscatalysis from fundamental studies to industrialcatalysis.

The 41. Jahrestreffen Deutscher Katalytikerwill again take place in Weimar, from 27th to 29thFebruary 2008 (3).

References1 40. Jahrestreffen Deutscher Katalytiker,

DECHEMA Gesellschaft für Chemische Technikund Biotechnologie e.V.: http://events.dechema.de/katalytiker07.html

2 Enterprise, Automotive Industry, MVEG:http://ec.europa.eu/enterprise/automotive/mveg_meetings/index.htm

3 41. Jahrestreffen Deutscher Katalytiker,DECHEMA Gesellschaft für Chemische Technikund Biotechnologie e.V.:http://events.dechema.de/katalytiker08.html

The Reviewer

Thomas Ilkenhans is a Research Chemist inthe Gas Phase Catalysis Group at the JohnsonMatthey Technology Centre. He is interested inusing palladium in catalysis.

“Metal-catalysis in Industrial Organic Pro-cesses” fills the gap in the market between text-books on homogeneous or heterogeneous catalysisand treatises on particular processes, typicallyavailable in the form of specialist reviews. It ispitched as an “advanced general textbook forchemistry students and their teachers; it will also bewelcomed by researchers in industrial andGovernment laboratories”. In my opinion thesetarget audiences are very well catered for by thisexcellent textbook. The field of industrial catalysisis obviously enormous and yet has been well cov-ered here in fewer than 300 pages. This makes thebook an accessible work that describes many of themore important processes in sufficient depth,rather than an unwieldy tome.

The introduction (P. Howard, G. Morris andG. Sunley) gives a good overview of the generalprinciples of catalysis in the industrial sector.These include the scales of various processes andfactors that affect process development, such aseconomics, feedstock availability, safety and envi-ronmental considerations. Chapter 2 (M. G.Clerici, M. Ricci and G. Strukul) covers the forma-tion of carbon–oxygen bonds by oxidation,beginning with the basic interactions of oxygenwith transition metal centres. It then focuses onlarge-scale commercial applications such as theformation of adipic acid, terephthalic acid, ethyl-ene oxide and phenols. Asymmetric epoxidationand dihydroxylation reactions are explored withregard to their application to the synthesis of finechemical and pharmaceutical intermediates.

Chapter 3 (L. A. Oro, D. Carmona andJ. M. Fraile) covers hydrogenation reactions, begin-ning with an overview of homogeneous andheterogeneous reaction pathways. The industrial

application of heterogeneous catalysis focuses onthe hydrotreating of petrochemicals, the hydro-genation of fats and the reduction of adiponitrile.Asymmetric homogeneous hydrogenation is cov-ered in depth. Specific industrially importantexamples are given, including the syntheses of L-DOPA, (S)-metolachlor and (–)-menthol, allusing rhodium-based catalysis. The next chapter(P. Maitlis and A. Haynes) describes industrialprocesses based on carbon monoxide. The first ofthe three main areas covered is the synthesis ofacids and anhydrides from alcohol carbonylationreactions. The historical development of aceticacid synthesis leads on to the growth of theMonsanto (1) and BP CativaTM (2) processes usingrhodium and iridium respectively. Similarly, thesection on hydroformylation covers the develop-ment of the cobalt-catalysed process through tothe use of rhodium-based systems, with a concisedescription of asymmetric hydroformylation. Thefinal part of the chapter focuses on the Fischer-Tropsch reaction.

Chapter 5 (F. Calderazzo, M. Catellani and G. P.Chiusoli) describes C–C bond-forming reactions.This starts with the use of Lewis acid catalysis in thealkylation of aromatic compounds and then pro-gresses to palladium-catalysed coupling reactions.Industrially significant examples are given, includingthe synthesis of sartans for the pharmaceuticalindustry and the fungicide boscalid, this is followedby a particularly informative discussion on why pal-ladium-catalysed cross-coupling reactions have notmade the inroads into the industrial sector thatmight be expected. The next section of the chapterdetails the use of allylic substrates in industrial catal-ysis. This chapter also includes the oligomerisationof alkenes, for instance in the synthesis of alkenes


“Metal-catalysis in Industrial OrganicProcesses”EDITED BY G. P. CHIUSOLI (University of Parma, Italy) and P. M. MAITLIS (The University of Sheffield, U.K.), RSC Publishing,

Cambridge, U.K., 2006, 290 pages, ISBN 978-0-85404-862-5, £99.95, U.S.$189.00

Reviewed by Robin B. BedfordSchool of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.; E-mail: [email protected]

DOI: 10.1595/147106707X235133


for the Shell Higher Olefins Process (SHOP), asopposed to olefin polymerisation which is coveredin depth in a later chapter (Chapter 7) by G. Finkand H.-H. Brintzinger. The SHOP process itself iscovered in Chapter 6 (C. L. Dwyer) which detailsthe metathesis of olefins, with ruthenium catalysisprominent. This chapter also describes emergingtechnologies that are likely to impact on futureapplications of metathesis in the commercial sector.

Concluding Remarks Given that most readers’ interests will tend to

lie either with homogeneous or heterogeneouscatalysis, the provision of two appendices onorganometallic chemistry and catalysis, and onbasic concepts of surface science related to hetero-geneous catalysis, is invaluable. An appendix onthe kinetics of catalysis would have been useful asthis is an area that is unfortunately not addressedto any great extent in the book.

In general the text is liberally supported by theuse of ‘boxes’ and annexes that detail interestingasides, important concepts or emergent technolo-gies. A particularly appealing aspect of the book isthe inclusion of ‘discussion points’ throughout the

text. These would be useful, for instance, asthemes for round-table discussions with advancedlevel undergraduate and postgraduate students,indeed I have used some of them for precisely thispurpose. In some of the chapters these are supple-mented with invaluable extra ‘hints’ to help get theball rolling. In summary I wholeheartedly recom-mend this excellent textbook to anybody with aninterest in catalysis, either from an industrial oracademic perspective.

References1 J. F. Roth, Platinum Metals Rev., 1975, 19, (1), 122 J. H. Jones, Platinum Metals Rev., 2000, 44, (3), 94

The ReviewerHaving graduated in biochemistry from theUniversity of Sussex, U.K., Robin Bedfordundertook a D.Phil. in organometallic catalysiswith Penny Chaloner (also at Sussex). He thenheld a postdoctoral research associateshipwith Anthony Hill at Imperial College Londonand lectureships in inorganic chemistry atTrinity College, Dublin and the University ofExeter, where he was promoted to Reader in

Catalysis. He moved to the University of Bristol in a similar role in2005. He currently holds an EPSRC Advanced Research Fellowshipand the Royal Society of Chemistry’s Sir Edward FranklandFellowship (Dalton Division) for 2006/7.

189Platinum Metals Rev., 2007, 51, (4), 189–198

DOI: 10.1595/147106707X232893

Work has been ongoing in building a thermo-dynamic database for the prediction of phaseequilibria in Pt-based superalloys (1–5). The alloysare being developed for high-temperature applica-tions in aggressive environments. The database willaid the design of alloys by enabling the calculationof the composition and proportions of phases pre-sent in alloys of different compositions. Currently,the database contains the elements platinum, alu-minium, chromium and ruthenium. This paper is arevised account of work presented at the confer-ence: Southern African Institute of Mining andMetallurgy ‘Platinum Surges Ahead’ at Sun City,South Africa, from 8th to 12th October 2006 (5).

Part I, describing initial results for the Pt-Al-Rusystem from the compound energy formalismmodel, was published in the July 2007 issue ofPlatinum Metals Review (1).

For the Ru-Al system, very good agreement hasbeen obtained between experimental phase equi-librium data and calculations based on a version ofthe compound energy formalism model (1).However, for the other binary and ternary systems,there are insufficient data to obtain good results bythis method, since more phases are represented ineach system. This paper (Part II) describes the dif-ferent approach which was needed, with simplerrepresentation to allow for sparse data.

Building a Thermodynamic Database forPlatinum-Based Superalloys: Part IIUSE OF MODELS REQUIRING FEWER PARAMETERS

By A. Watson*Institute for Materials Research, University of Leeds, Leeds LS2 9JT, U.K.; *E-mail: [email protected]

R. Süss**Advanced Materials Division, Mintek, Private Bag X3015, Randburg 2125, South Africa,

DST/NRF Centre of Excellence in Strong Materials, Johannesburg 2050, South Africa,

and School of Chemical and Materials Engineering, University of the Witwatersrand, Private Bag 3, Johannesburg 2050,

South Africa; **E-mail: [email protected]

and L. A. Cornish†

Advanced Materials Division, Mintek, Private Bag X3015, Randburg 2125, South Africa,

DST/NRF Centre of Excellence in Strong Materials, Johannesburg 2050, South Africa,

and School of Chemical and Materials Engineering, University of the Witwatersrand, Private Bag 3, Johannesburg 2050,

South Africa; †E-mail: [email protected]

Work is being done at Mintek, the University of Leeds and the University of Bayreuth tobuild up a platinum-aluminium-chromium-ruthenium (Pt-Al-Cr-Ru) database for the predictionof phase diagrams for further alloy development by obtaining good thermodynamic descriptionsof all of the possible phases in the system. Binary descriptions were combined, allowingextrapolation into the ternary systems, and experimental phase equilibrium data were comparedwith calculated results. Very good agreement was obtained for the Pt-Al-Ru system, as describedin Part I of this series of papers (1). This paper (Part II) addresses the Pt-Cr-Ru system,with equally encouraging results. The final paper in the series (Part III, to be published in afuture issue of Platinum Metals Review) will deal with work on the platinum-aluminium-chromium-nickel (Pt-Al-Cr-Ni) database at the University of Bayreuth. The Pt-Al-Cr-Ruand Pt-Al-Cr-Ni databases will eventually be merged.


Part III will complete the series by describingwork at the University of Bayreuth on the plat-inum-aluminium-chromium-nickel (Pt-Al-Cr-Ni)database, which is eventually to be merged withthe Pt-Al-Cr-Ru database.

Simple Phase Representation:General Considerations

Concerning the (Pt) and Pt3Al phases, there isdisagreement on which particular model should beused. These phases are similar to (Ni) and Ni3Alrespectively. (Here, (Pt) and (Ni) denote combina-tions of four atoms of the elements in thefour-compound sublattice formalism (CSF); arith-metically, Pt4 and Ni4 respectively.) One school ofthought states that as all four phases are based onthe f.c.c. lattice, then Ni3Al, which can be viewedas an ordered f.c.c. phase, should be included asthe f.c.c. phase in modelling (Pt) and Pt3Al. On theother hand, another school of thought stipulatesthat, since (Pt) and Pt3Al solidify separately, theyshould be modelled separately. The second schoolof thought would allow for Pt3Cr and PtCr to bemodelled as part of (Pt), since they form by order-ing within the (Pt) phase field at lowertemperatures. This might be considered as anom-alous in that Pt3Al would not be incorporated inthe f.c.c. model, whereas Pt3Cr would be.However, given that phases should be modelled inthe same way only if they are likely to be contigu-ous, this would not be a problem unless Pt3Al islikely to be contiguous with Pt3Cr. At the moment,this is not likely. A similar argument can be madefor Pt3Al, which just like Ni3Al, solidifies as a sep-arate phase from (Pt), and is not formed within.

Another source of contention is that in themodel being developed here, many parameters areneeded to describe the phase. For the Ni-Al sys-tem, it could be argued that there are many datapoints and that the large number of parameters isjustified. However, for Pt-Al, not only are therefewer data points, but there is also much greateruncertainty in the binary phase diagram regardingthe reaction temperatures involving Pt3Al, andeven the type of ordering. Thus, a much simplermodel is prescribed for the Pt3Al phase, bothbecause of a dearth of data (as compared with

Ni3Al), and also because the Pt3Al and (Pt) phasessolidify separately. All the information regardingordering needs to be gathered before any incorpo-ration into modelling is attempted. However, itmust be noted that in the Dupin database (6), theNi3Al phase is modelled as ordered f.c.c., eventhough it solidifies separately. The latest databasefrom Dupin (6) was used to draw the Ni-Al phasediagram, and the γ/γ' boundary did not agree wellwith that in the experimental phase diagram, so itis questionable whether Dupin’s complex model-ling is really worthwhile.

It is best to adopt the most appropriate modelfor each phase in the system on the basis of itscrystal structure and the available experimentaldata. Simple substitutional solid solutions can bemodelled with two sublattices; one sublattice ofsites of mixed occupancy (by the substituting ele-ments) and one of interstitial sites. Ordered phaseshave a more complex crystallography in that atomshave preferential site occupancy. These phases aremodelled with a more complex sublattice modelcomprising multiple sublattices with mixing of anumber of different elements on each, dependingon the crystallography. Although a multiple sub-lattice model is more complex than a simpletwo-sublattice model, it is easier to use the formerto describe phases with a limited homogeneityrange. In the extreme case, a stoichiometric phaseis thus modelled with a single component on eachsublattice. It is often useful to model an orderedphase along with its disordered ‘parent’ phase, forexample b.c.c._B2 and b.c.c._A2, or f.c.c._L12 andf.c.c._A1, with a single Gibbs energy descriptionenabling the ordering transition to be modelled.This modelling is quite complex, and whether suchcomplications should be included depends on theapplication of the database.

There are databases being developed withoutsuch complex modelling and these are very useful.One example is the COST 531 lead-free soldersdatabase (7), comprising assessed thermodynamicdata for binary and ternary systems based on elevenelements associated with lead-free solder materials.Thus, it might be questioned whether the currentpgm database should be concerned with order/dis-order reactions. The answer should be positive, of


course, because the ordered Pt3Al phase, which isan ordered f.c.c. phase, is the basis of the alloys.However, if there are too few experimental dataavailable, modelling the Pt3Al and f.c.c._A1 phasewith a single Gibbs energy description will be diffi-cult. If a model requiring many parameters isoptimised with few data points, the parametersthemselves become meaningless and the results arehighly unlikely to be representative. Thus, in thecurrent work, it was decided to model such orderedphases separately and then extend the databasesubsequently if there is both sufficient need and theexperimental data become available. In this way,the database grows with the available experimentaldata, and at any time, the database is the optimumthat can be achieved. Currently, the database isbeing developed so that the phase equilibriabetween the phases on solidification can bederived. As more work is done on developing thealloys for application, the order/disorder reactionswill become increasingly important, especially forthe Pt3Al phase. A combination of Thermo-CalcTM

(8), Pandat (9) and MTDATA (10) software wasused for the present work.

Chromium-PlatinumUntil experimental results show otherwise, the

assessment of Oikawa et al. (11) will be used,extrapolated into the ternary, and will then bereoptimised with experimental values from the Pt-Cr-Ru system. The assessment of Oikawa et al. (11)

is shown in Figure 1. However, it was necessary toderive Gibbs energy parameters for the metastableh.c.p. phase in the binary system. The metastablephase was initially allocated the same set of Gibbsenergy values as for the f.c.c. phase, but the para-meters were optimised using the ternary data(described below).

Platinum-RutheniumIt was initially thought that the description of Pt-

Ru in the Spencer database (12) version ofPt-Ru would be the same as that in the ScientificGroup Thermodata Europe (SGTE) database (13).However, this was not so. The phase diagram fromSpencer is a eutectic, with a maximum in (Pt) and ~ 10ºC between the maximum and eutectic temper-ature, whereas that from SGTE is peritectic, whichis consistent with available literature (14, 15) andexperimental work at Mintek.

Optimising with data from Hutchinson (14)gave a good fit and convincing coefficients. Whileplotting the free energy curves demonstrated thatRu had an unusual energy curve, it would be unwiseto change this feature, because it originated fromthe Ru unary data, is set across the entire database,and represents a best-fit value for many systems.One solution to this anomaly would be to add aninteraction parameter, but it must be rememberedthat there are too few data available. However, itwas found that the most reasonable fit to the phaseboundaries of the (Pt) + (Ru) two-phase field,

0 20 40 60 80 100Pt, at.%

2000

1800

1600

1400

1200

1000

800

Tem

pera

ture

, ºC

Cr3Pt

Müller [51]Waterstrat [52]Waterstrat [52]

f.c.c.

b.c.c.

Liquid

Fig. 1 Cr-Pt phase diagramcalculated by Oikawa et al. (11)(Courtesy of Elsevier Science;reference numbers are as cited inReference (11))


where a few compositions had been measuredexperimentally, resulted in the appearance of a veryshallow eutectic reaction. The phase diagram, opti-mised using WinPhaD and calculated using Pandat,is given in Figure 2, and may be compared with theexperimental diagram in Figure 3.

Chromium-RutheniumThis system contains two intermetallic com-

pounds: Cr2Ru (σ) and Cr3Ru. The accepted models

have three sublattices, so this format would be fol-lowed for the Cr-Ru system despite the fact that,especially given such limited data, it would be diffi-cult to have mixing on all three sublattices – manyend-members would be needed. It was thereforedecided that Cr only would be located on one sub-lattice, and the remaining two would have mixing;this is normal practice. The current model of choicefor the σ phase is 10:16:4 (where the notation showsthe numbers of atoms on each of the three

3000

2500

2000

1500

1000

500

Tem

pera

ture

, ºC

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1Ru, mole fraction

Liquid

f.c.c._A1

h.c.p._A3

2400

2200

2000

1800

1600

1400

1200

1000

Tem

pera

ture

, ºC

0 10 20 30 40 50 60 70 80 90 100Ru, at.%

Ru, wt.%0 10 20 30 40 50 70 100

Liquid

1769.0ºC

(Pt) (Ru)

70 79

62 80

2334ºC

Fig. 2 Pt-Ru phase diagram: Bestcalculated diagram to date

Fig. 3 Pt-Ru phasediagram:Experimental from(15) (Courtesy ofASM International)


sublattices; the previous model was 8:18:4). Theprevious model featured in the Glatzel assessment(16), although with mixing on all three sublattices.Elements are usually mixed on many sublatticesonly where there is a very wide range of phase sta-bility. In this case, there is a narrow phase stabilityrange, so the degree of mixing needs to be reduced.

The approach used was to build up the systemwith the most simple phase diagram descriptionspossible: thus Cr2Ru (σ) and Cr3Ru would be linecompounds. The Ru and Cr unary data werederived from Kaufman (17). Since Kaufman’s (17)reported reaction temperatures involving Cr2Ru (σ)and Cr3Ru were suspiciously convenient: ~ 750, ~ 800 and ~ 1000ºC, it was realised that there wereproblems with the system, and the rounded data arethe best that were obtained from the literature (15).These had to be used, as there are no other dataavailable. Attempts to measure the reaction temper-atures by differential thermal analysis (DTA) wereinconclusive (18). The phase diagram gave a verygood fit, as shown in Figure 4, compared with theexperimental diagram (Figure 5) (15).

Platinum-Chromium-RutheniumExperimental results of the A15 Cr3Ru and

Cr3Pt phases were not conclusive in showingwhether the phases are contiguous, despite two

more samples of intermediate compositionsbetween Cr3Ru and Cr3Pt being prepared at Mintek.These samples were annealed at ~ 850ºC, because ifthe phases are contiguous, they should meet at thistemperature for the sample compositions chosen.Depending on how the phases extend into theternary, the sublattice on which substitution isoccurring can be determined. For Cr3Ru, if Ru isconstant, then Pt substitutes for Cr; and for Cr3Pt,if Cr is constant, Ru substitutes for Pt. It must,however, be remembered that the original sampleswere not in equilibrium, and the latest samples wereannealed for longer, to promote equilibrium.

It should be noted that Waterstrat’s Cr3Pt phase(19) was more narrow (almost stoichiometric) anddid not decompose at lower temperature (which iswhat was calculated at one stage in the presentwork). A likely model for this case (19) would be Cron one sublattice and Pt + Cr on the other, but thisdepends on the atomic sizes. These can be mea-sured in different ways (giving different results) andthe most appropriate method should be used forthe mode of bonding of the particular atom. Pt andRu show similar covalent radii. This being so, theycould sit on the same sublattice. However, it is recommended that other A15 phases beresearched to see how they would best bemodelled, especially for the composition

Tem

pera

ture

, ºC

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1Ru, mole fraction

3000

2500

2000

1500

1000

500

Liquid

b.c.c._A2

h.c.p._A3

h.c.p._A3+Cr2Ru

Cr3Ru

Fig. 4 Cr-Ru phase diagram: Bestcalculated diagram to date


ranges (i.e. the spread on both sides from molefraction X = 0.25). For the representation of Cr3Ptwithin the ternary (and higher-order phase dia-grams), the model would be much simpler (andhave fewer end members) if the lattice componentscould be described as (Cr, Cr) (Cr, Pt, Ru).

To model the ternary system, an interactionparameter, added to increase the phase extensionsinto the ternary, was determined for the h.c.p.phase. The projected liquidus surface, shown inFigure 6, is an improvement on the assessment byGlatzel et al. (16). However, the invariant reactionsare still incorrect, because Figure 6 shows the liq-uidus surfaces for (Ru) and Cr3Pt abutting, bycontrast with the experimental results in Figure 7.Those for (Cr) and (Pt) should in fact abut, becauseof the (Pt) + (Cr) eutectic observed in the ternarysamples (20, 21). However, the junction betweenthe incorrect surfaces of primary solidification issmaller than was calculated previously (16), andagrees more closely with the experimental results.

The thermodynamic description of the ternarysystem was optimised using the experimental dataof Zhao (22), as this set of data seemed to be morecomplete and self-consistent, and Mintek’s data(20, 23) were affected by coring. The assessmentmodule of MTDATA was used to perform theoptimisation. During the optimisation process it

was found that it was necessary to adjust only theGibbs energy description of the metastable h.c.p.phase in the Cr-Pt binary in order to get a reason-able fit to the experimental phase diagram data forthe f.c.c. and h.c.p. phase boundaries. No ternaryinteractions were required for these phases (24).

The experimental data for the A15 phase fittedreasonably well, although the fit was little improvedby allowing the optimisation to give a Gibbs ener-gy description for the metastable Pt3Ru A15 phase.The A15 phase extends from the Cr-Pt edge asrequired but too far into the ternary. Also, the A15phase field is not wide enough as it extends into theternary. This feature is probably due to the fact thatthe phase is modelled with a very narrow homo-geneity range in the Cr-Ru system. Bettermodelling of the A15 phase in the binary systemwould undoubtedly improve the overall modellingof this phase, but this would require further exper-imental study of its stability range. The fit to theexperimental b.c.c. phase diagram data is, however,very good. The calculated phase diagram for1200ºC, showing the experimental data, is given inFigure 8. The fit with the experimental data fromSüss et al. (23) is not so good, particularly withrespect to the (Ru) h.c.p. phase boundary, but thiscould be due to coring effects. Again, this could beimproved by a better description of the A15 phase.

2500

2000

1500

1000

500

Tem

pera

ture

, ºC

0 10 20 30 40 50 60 70 80 90 100Ru, at.%

Ru, wt.%0 10 20 30 40 50 60 70 80 90 100

Liquid

1863ºC

1610ºC1580ºC

~ 800ºC

~ 1000ºC

~ 750ºC

(Cr) (Ru)

~ 37

~ 48

~ 23

σ

2334ºC

~ 33Cr 3R

u~ 32

Fig. 5 Cr-Ru phasediagram: Experimentalfrom (15) (Courtesy ofASM International)


0 0.2 0.4 0.6 0.8 1Pt, mole fraction

0.2

1

0.6

0.8

0.4

Ru

Cr Pt

Ru, m

ole

fract

ion

Fig. 6 Liquidus surface for the Pt-Cr-Ru system: Best calculated surface to date

L → Cr3Pt + (Cr) at 1500ºC L → Cr3Pt + (Pt) at 1530ºC

Cr3Pt

(Cr)

(Ru)

(Pt)

L → (Ru) + (Cr)at 1610ºC

L + (Ru) → (Pt)at 2100ºC

(Ru)

Ru

PtCr

1

2

Fig. 7 Liquidus surface for the Pt-Cr-Ru system: Experimental from (20, 21) (Courtesy of ElsevierScience and the African Materials Research Society). Reaction 1: L + (Ru) ↔ (Pt ) + (Cr); Reaction 2: L + (Cr) ↔ (Pt ) + Cr3Pt


The calculated phase diagram for 1000ºC is givenin Figure 9.

ConclusionThe latest developments to the Pt-Al-Cr-Ru

database have improved the agreement with theexperimental phase diagrams, and especially withdiffusion data. The models of the f.c.c., Cr3Ru andCr2Ru (σ) phases were changed, and the new mod-els were selected so that fewer parameters werenecessary. However, the order/disorder reactionsof the f.c.c. phases have yet to be modelled suc-cessfully, and before this can be realised moreexperimental data are needed. The A15 phaseneeds to be modelled in order to produce a widerphase range within the ternary. Once again, moreexperimental data are needed to confirm whetherthe A15 phases in the Cr-Pt and Cr-Ru systems arecontiguous. More samples between the two binaryphases had been manufactured, annealed at inter-mediate temperatures and analysed, but the resultswere not conclusive. Thus, future work on the

database can only be undertaken once more exper-imental data have been acquired.

Work is in hand at the University of Bayreuthon the platinum-aluminium-chromium-nickel (Pt-Al-Cr-Ni) database, which is eventually to bemerged with the Pt-Al-Cr-Ru database. Part III ofthis series of papers, to be published in a futureissue of Platinum Metals Review, will describethis work.

AcknowledgementsFinancial assistance from the South African

Department of Science and Technology (DST);the Platinum Development Initiative (PDI: AngloPlatinum, Impala Platinum and Lonmin);DST/NRF Centre of Excellence in StrongMaterials; and Engineering and Physical SciencesResearch Council (EPSRC) Platform GrantGR/R95798 is gratefully acknowledged. Theauthors would like to thank CompuTherm LLC,Wisconsin, U.S.A., and the National PhysicalLaboratory (NPL), Teddington, U.K., for the

Cr 0.8 0.6 0.4 0.2 RuCr, mole fraction

f.c.c.h.c.p.A15b.c.c.

0.2

0.6

0.8

0.4

Pt

Pt, m

ole

fract

ion

b.c.c._A2

f.c.c._A1

h.c.p._A3

0.8

0.6

0.4

0.2

Ru, mole fraction

A15

Fig. 8 Calculated isothermal section for the Pt-Cr-Ru system for 1200ºC with experimental data fromZhao (22) (Courtesy of Springer)


provision of the WinPhaD, Pandat and MTDATAsoftware. This paper is published with the per-mission of Mintek and the Southern AfricanInstitute of Mining and Metallurgy.

Cr 0.8 0.6 0.4 0.2 RuCr, mole fraction

h.c.p.b.c.c.A15f.c.c.Cr2Ru

0.2

0.6

0.8

0.4

Pt

Pt, m

ole

fract

ion

b.c.c._A2

f.c.c._A1

h.c.p._A3

0.8

0.6

0.4

0.2

Ru, mole fraction

A15

Fig. 9 Calculated isothermal section for the Pt-Cr-Ru system for 1000ºC with experimental data fromSüss et al. (23) (Courtesy of Elsevier Science)

References1 L. A. Cornish, R. Süss, A. Watson and S. N. Prins,

Platinum Metals Rev., 2007, 51, (3), 1042 I. M. Wolff and P. J. Hill, Platinum Metals Rev., 2000,

44, (4), 1583 L. A. Cornish, J. Hohls, P. J. Hill, S. Prins, R. Süss

and D. N. Compton, J. Min. Metall. Sect. B: Metall.,2002, 38, (3–4), 197

4 L. A. Cornish, R. Süss, L. H. Chown, S. Taylor, L.Glaner, A. Douglas and S. N. Prins, ‘Platinum-BasedAlloys for High Temperature and SpecialApplications’, in “International PlatinumConference ‘Platinum Adding Value’”, Sun City,South Africa, 3rd–7th October, 2004, SymposiumSeries S38, The South African Institute of Miningand Metallurgy, Johannesburg, South Africa, 2004,pp. 329–336

5 L. A. Cornish, R. Süss, A. Watson and S. N. Prins,‘Building a Database for the Prediction of Phases inPt-based Superalloys’, in “Second InternationalPlatinum Conference ‘Platinum Surges Ahead’”, SunCity, South Africa, 8th–12th October, 2006,Symposium Series S45, The Southern AfricanInstitute of Mining and Metallurgy, Johannesburg,South Africa, 2006, pp. 91–102; http://www.plat-inum.org.za/Pt2006/index.htm

6 B. Sundman and N. Dupin, in: “XXIX JEEP:Journées d’Étude des Équilibres entre Phases”,Lyon Villeurbanne, France, 2nd–3rd April, 2003,eds. F. Bosselet, C. Goutaudier et al., Journal dePhysique IV – Proceedings, EDP Sciences, Les Ulis,France, 2006

7 A. Watson, A. Dinsdale, A. Kroupa, J. Vízdal, J.Vrestal and A. Zemanová, “The COST 531 Lead-free Solders Thermodynamic Database”,Proceedings of the 61st Annual ABM Congress, Riode Janeiro, Brazil, 24th–27th July, 2006

8 B. Sundman, B. Jansson and J.-O.Andersson,CALPHAD, 1985, 9, (2), 153

9 S.-L. Chen, S. Daniel, F. Zhang, Y. A. Chang, X.-Y.Yan, F.-Y. Xie, R. Schmid-Fetzer and W. A. Oates,CALPHAD, 2002, 26, (2), 175

10 R. H. Davies, A. T. Dinsdale, J. A. Gisby, J. A. J.Robinson and S. M. Martin, CALPHAD, 2002, 26,(2), 229

11 K. Oikawa, G. W. Qin, T. Ikeshoji, O. Kitakami, Y.Shimada, K. Ishida and K. Fukamichi, J. Magn. Magn.Mater., 2001, 236, (1–2), 220 and references therein

12 P. J. Spencer, The Noble Metal Alloy (NOBL)Database, The Spencer Group, Trumansburg,U.S.A., 1996

13 A. T. Dinsdale, CALPHAD, 1991, 15, (4), 31714 J. M. Hutchinson, Platinum Metals Rev., 1972, 16, (3),

8815 “Binary Alloy Phase Diagrams”, 2nd Edn., eds. T. B.

Massalski, H. Okamoto, P. R. Subramanian and L.Kacprzak, in 3 volumes, ASM International, Ohio,U.S.A., 1990

16 U. Glatzel and S. N. Prins, ‘ThermodynamicAssessments of the Pt-Cr and Cr-Ru Systems withan Extrapolation into the Pt-Cr-Ru System’, in“CALPHAD XXXII: Program and Abstracts”,Quebec, Canada, 25th–30th May, 2003, p. 118; seeC. K. Pollard, CALPHAD, 2004, 28, (3), 241

17 L. Kaufman and H. Bernstein, “ComputerCalculation of Phase Diagrams, with Special

Reference to Refractory Metals”, Academic Press,New York and London, 1970, p. 60

18 R. Süss and L. A. Cornish, ‘Possible Changes to theCr-Pt Binary Phase Diagram’, in Proc. Microsc. Soc.south. Afr., Vol. 35, Kwazulu-Natal, 5th–7thDecember, 2005, p. 9

19 R. M. Waterstrat, J. Less Common Met., 1981, 80, (1),P31

20 R. Süss, L. A. Cornish and M. J. Witcomb, J. AlloysCompd., 2006, 416, (1–2), 80

21 R. Süss, U. Glatzel, S. N. Prins and L. A. Cornish, ‘AComparison of Calculated and ExperimentalLiquidus Surfaces for the Pt-Cr-Ru System’, inSecond International Conference of the AfricanMaterials Research Society, University of theWitwatersrand, Johannesburg, 8th–11th December,2003, pp. 141–142

22 J.-C. Zhao, J. Mater. Sci., 2004, 39, (12), 391323 R. Süss, L. A. Cornish and M. J. Witcomb,

‘Investigation of Isothermal Sections at 1000 and600ºC in the Pt-Cr-Ru System’, J. Alloys Compd., inpress

24 A. Watson, L. A. Cornish and R. Süss, Rare Met.,2006, 25, (5), 597

The AuthorsDr Andy Watson is a Senior Research Fellow inthe Institute for Materials Research at theUniversity of Leeds. He has worked inexperimental and computationalthermodynamics for many years and hasinterests in lead-free solders and intermetallicphases as well as pgm alloys.

Rainer Süss is Section Head of the AdvancedMetals Group in the Advanced Metals Divisionat Mintek, as well as the co-ordinator of theStrong Metallic Alloys Focus Area in theDST/NRF Centre of Excellence for StrongMaterials. His research interests include phasediagrams, platinum alloys and jewellery alloys.

Lesley Cornish is the Director of the DST/NRFCentre of Excellence in Strong Materials and anHonorary Professor at the University of theWitwatersrand, South Africa. She is associatedwith Mintek. Her research interests includephase diagrams, platinum alloys andintermetallic compounds.

198Platinum Metals Rev., 2007, 51, (4)

The 21st annual Santa Fe Symposium® was heldin Albuquerque, New Mexico, from 20th to 23rdMay 2007 (1). Yet again, this well-attended interna-tional symposium covered a wide range oftechnical topics but the strongest interest was inpalladium as a jewellery material (see also (2)).There is no doubt that palladium jewellery is caus-ing excitement in the manufacturing industry and,as delegates heard in discussion, there is increasingrecognition that palladium is quite different in itsmanufacturing behaviour from platinum.

The Symposium commenced with a thought-provoking keynote presentation by Andrea Hill(CEO, The Bell Group, U.S.A.), entitled ‘Top LineFocus’, in which she discussed the business-ledapproach to running a jewellery manufacturingfirm. The three key themes were: (a) knowing yourbusiness, (b) revenue numeracy and (c) attention toplanning. The technical sessions followed, firstlywith Chris Corti (COReGOLD, U.K.) introducing‘Basic Metallurgy of the Precious Metals’ to thedelegates, and discussing the metallurgical basis forthe various precious metal jewellery alloys, in-cluding those of platinum and palladium, and howalloy properties can be tailored by compositionand microstructure to suit the application or manufacturing route.

PalladiumMark Mann (Mann Design Group, U.S.A.)

spoke on ‘950 Palladium: Manufacturing Basics forServicing, Assembly and Finishing’. He started hispresentation by discussing the basic properties ofpalladium that make it attractive as a jewellerymetal and how to distinguish it from platinum andwhite gold, using the non-destructive iodine test(3). He then launched into a comprehensive reviewof the working behaviour of palladium in relation

to general jewellery manufacturing. He covered thepractical aspects of annealing, contamination, sol-dering and welding (by torch and laser), formingand shaping, engraving, finishing and setting. Thepresentation was supported by a number of casestudies of hand techniques, such as ring sizing.While palladium solders are available, he demon-strated that low-melting platinum-based solderscould be used. The information presented in thispaper will form the basis of a new jewellery techni-cal manual being produced by Johnson Mattheyfor the industry (3).

The welding of palladium was further discussedin a presentation by Kevin Lindsey (LindseyJewelers, U.S.A.), entitled ‘How To Get the BestResults Welding Palladium: A Comparative Study’.This was the result of a study of the tungsten inertgas (TIG) welding of two 950 palladium alloys,from Johnson Matthey and Hoover & Strong, inwhich several welding parameters were varied. Themodel configuration for the test welds was a ringshank, 4 mm × 1.5 mm. The welds were tested bybending to failure. Two tungsten electrode sizeswere tested and pure argon was used as the covergas. Copper plate was used as the welding sub-strate. Depending on welding conditions, somecratering and poor penetration were obtained insome test welds, but good welds could be obtainedin both palladium materials under the correct con-ditions. The Johnson Matthey alloy performedbetter in terms of cycles of bending to failure,attaining 94% of the cycles to failure of theunwelded bar stock. The Hoover & Strong alloyshowed better flow during welding, but poorerperformance in terms of cycles to failure (70% ofbar stock). The optimal welding parametersdepend on the alloy. Lindsey gives a set of startingvalues suitable for both alloys which will give


The 21st Santa Fe Symposium on JewelryManufacturing Technology TECHNICAL INTEREST IN PALLADIUM REMAINS STRONG IN THE INDUSTRY

Reviewed by Christopher W. CortiCOReGOLD Technology Consultancy, Reading, U.K.; E-mail: [email protected]

DOI: 10.1595/147106707X234242


reasonable initial welds and serve as a basis foroptimisation. The overall conclusion is that 950palladium alloys can be satisfactorily joined byTIG welding.

A comparative study of the manufacture offindings was presented by Fred Klotz (Hoover &Strong, U.S.A.): ‘A Comparison of Nickel WhiteGold, Palladium White Gold and 950 Palladium inthe Manufacture of Findings’. He compared theperformance of 950 palladium with those of 14carat and 18 carat nickel- and palladium-whitegolds and 950 platinum-ruthenium alloys for themanufacture of both die-struck and cast settings.He noted that both the 950 platinum and palladi-um alloys showed a comparable degree ofwhiteness (as measured by the ASTM YellownessIndex (4, 5)), and better whiteness than the Grade1 white golds used in the study. The cold forgingtests were performed on wire stock, 0.1 inch diam-eter, in conventional steel dies, using conditionsoptimised for the white golds. Klotz noted that allalloys cold-forged well, but that the platinum-ruthenium alloy performed not quite so wellduring blanking operations. In cold forging, metal-lography revealed the flow of metal around theedge into the overflow area. The 950 palladiumalloy flowed well and annealed to a fine grain struc-ture. In assembly tests, all the blanked settingsassembled satisfactorily, although the platinum set-tings showed more drag as they slid together,probably due to their rougher sheared edges fromblanking. The 950 palladium blanks were softerthan the other alloys and more care had to betaken to stop them bending or distorting whenpressure was applied. Soldering tests with a torchshowed good solder flow for both palladium andplatinum settings.

Machining tests were conducted on weddingbands using polycrystalline diamond tools. Asexpected, the platinum alloy was the most difficultto machine. The palladium alloy was also found tobe difficult compared with the gold alloys, whenthe same tool set-up as for platinum was used. Inaddition, investment casting tests on settingsshowed all alloys to cast well. Subsequent machinefinishing revealed few defects and all alloyspolished well.

Klotz concluded that both the platinum andpalladium alloys perform differently from thegolds, and processing needs to vary accordingly.

The use of metallography in jewellery fabrica-tion was discussed by Professor Paolo Battaini(8853 SpA, Italy) and illustrated by case studies ofdefects: ‘Metallography in Jewellery Fabrication:How to Avoid Problems and Improve Quality’.He demonstrated how it can be used to determinewhether annealing has resulted in satisfactoryrecrystallisation for example. Of particular notewas an instance of silicon contamination in a 950palladium alloy during investment casting thatcaused intergranular embrittlement.

PlatinumA review of casting tree design in the invest-

ment casting of platinum alloys was presented byJurgen Maerz (Platinum Guild International,U.S.A.): ‘Platinum Casting Tree Design’. Formany manufacturers of platinum jewellery, invest-ment casting is something of a challenge. Maerzbelieves many of the problems with investmentcasting are associated with tree design and sprue-ing techniques and he set out to de-mystify theprocess. This presentation included sound adviceon torch casting, where the metal is melted by gastorch, as well as the use of induction melting. Healso discussed various casting machine character-istics before focusing on tree design – describingthe ‘thick centre’ (central sprue) tree, the ‘no tree,button-casting’ design, the ‘diablo’ shaped tree,‘four wheel’ or circular-sprued tree, thin-spruetrees and inverted trees. Maerz addressed shellcasting and the tree/sprue design approach neces-sary for this method. In addition, he commentedon the various platinum alloys and their perfor-mance in casting. Finally, Maerz discussed a rapidmethod of torch casting that he introduced in1998 (6). Using investment powders derived fromthe dental industry, the entire casting process canbe accomplished in less than one hour, using a T-bar tree design. Maerz’s review was certainly verycomprehensive. It should benefit all castersof platinum jewellery and encourage newcasters to work with platinum with some degree of confidence.

A novel alloy development was the subject of apresentation by Boonrat Lohwongwatana(California Institute of Technology, U.S.A.): ‘Hard18K and .950 Pt. Alloys That Can Be ProcessedLike Plastics or Blown Like Glass’. This concernedbulk metallic glasses, or ‘amorphous or liquid met-als’ as they are known. In this study,Lohwongwatana has developed two bulk metallicglass (BMG) alloys for jewellery application(Figure 1). One is an 850 platinum containing cop-per, nickel and phosphorus; the other is a hard 18carat gold. After describing BMGs and their char-acteristics, in particular their glass transitiontemperature and the need to cool rapidly to pre-serve the amorphous structure (there is a criticalcooling rate), he went on to describe how suchmaterials can be processed with reference to atime-temperature diagram and the onset of crys-tallisation. BMGs can be moulded by blowing,injection moulding or by thermoplastic forming.

Shapes can also be obtained by casting, inwhich a crystalline structure can be obtained bycooling at less than the critical rate. Particularattention was given to thermoplastic processing inwhich BMG alloy grains (in the amorphous condi-tion) are heated above the glass transitiontemperature to become a viscous liquid, thenmoulded in dies or by blow forming. For the plat-inum alloy, processing can be done at 250 to270ºC. The processed alloy can be allowed to crys-tallise or cooled to maintain the BMG state.Enormous deformations can be obtained andinteresting shapes can be made, with very good

surface detail and finish. This is a very innovativedevelopment, ready for commercial exploitation.It will be interesting to see how the jewelleryindustry responds.

Under the title ‘Know Your Defects: TheBenefits of Understanding Jewelry Manufac-turing Problems’, Stewart Grice (Hoover &Strong, U.S.A.) discussed a number of case histo-ries of manufacturing defects and how use ofhardness testing, optical and electron microscopyand compositional analysis can be used to deter-mine the causes of defects and thus lead tosolutions to prevent recurrence. Among themany case histories discussed, Grice included oneon surface porosity on a 950 platinum-rutheniumalloy investment cast ring. The casting had afrosted appearance and gas porosity was suspect-ed. However, metallography of a cross-sectionrevealed the cause as massive shrinkage porosityin the head and shoulder areas of the ring.Modifying the sprue and gating solved the prob-lem. Another example on the same alloy involvedembrittlement of mill stock made from scrapsprues and surplus castings. The bar had failedcatastrophically after only two passes through therolling mill. The intergranular failure was exam-ined under the optical microscope and thepresence of a second phase at the grain bound-aries observed. Full chemical analysis revealedthe presence of 100 ppm of phosphorus, an ele-ment well known to cause embrittlement ofplatinum at levels of 50 ppm or less. The sourceof the phosphorus was probably the phosphate-


Fig. 1 Thermoplasticforming of 850 platinum bulkmetallic glass (BMG) fromBMG pellets (Courtesy of B.Lohwongwatana)

bonded investment mould material. Its presencewould indicate inadequate removal from thecasting scrap.

Progress in optimising the burnout characteris-tics of resin patterns produced by rapidprototyping/manufacturing technologies, was dis-cussed by Ian McKeer (SRS Ltd, U.K.), in terms oftheir use for direct investment casting:‘Improvements in the Burnout of Resin Patterns’.Clean burnout of the resin has been a major prob-lem. Casting, using platinum investments, showedsome problems with surface quality. The fast ‘den-tal’ cycle approach, described by Maerz (see above)did produce some improvements.

Other Papers of InterestMcKeer’s presentation was focused on product

quality and two further presentations took up thistheme. Alexandre Auberson (Cartier, U.S.A.)spoke about the testing of jewellery made byCartier to ensure ‘fitness for purpose’: ‘Tests forJewellery: A Must in the Development and QualityProcess’. Appropriate testing is a ‘must’ for bothproduct development and quality assurance.Auberson described a number of test methods andmachines developed by Cartier to simulate in-service conditions for wear, strength, flexibility,mechanical shocks, durability and tarnish and cor-rosion among others. Of particular interest andamusement to the audience was Cartier’s ‘simulat-ed handbag’ test, Figure 2, designed to simulate theeffects of jewellery kept in a woman’s handbag; asAuberson remarked, it can reveal inherent weak-nesses in jewellery construction.

Chris Corti (COReGOLD, U.K.) took up thequality theme, assessing progress made by the indus-try over the ten years since he first addressed thistopic and identified the need for industry-wide stan-dards: ‘Quality in the Jewellery Industry Beyond2000: A Review of Progress 1998–2006’.Appreciable progress has been made, for instance inadopting quality assurance schemes and definingwhite gold colour standards, but much remains to betackled, such as industry-standard product test pro-cedures, hallmarking standards and even basic alloydata sheets for the common alloys used in jewellery.

Klaus Wiesner (Wieland GmbH, Germany)

spoke about sheet metal manufacturing ofprecious metals, and addressed some basics interms of processing, defects and tolerances relatedto customer requirements: ‘Sheet MetalManufacturing – Some Basics’. Greg Raykhtsaum(Leach & Garner, U.S.A.) revisited the topic ofnickel testing of white gold and the amended EUDirective (7), showing how this modified regula-tion opens up new opportunities for nickel-containing golds: ‘White Gold Piercing Jewelry andthe “Nickel Directive”, 2004/96/EC’. There wereseveral presentations on tarnish measurement, inrelation to the new tarnish-resistant silvers on themarket. The need for improved tarnish test stan-dards and procedures was identified. This topicwas also taken up by Dippal Manchanda(Birmingham Assay Office, U.K.), who discussedrecent progress in amending the EU Directive, andthe Assay Office’s development of a new, fastertest procedure which is showing some promise asan alternative, accurate test: ‘ComparativePerformance of Nickel Release Test Procedures:PD CR 12471:2002 and EN 1811:1998’.

Two related presentations on computer model-ling of investment casting were made by Jörg


Fig. 2 Cartier handbag test (Courtesy of A. Auberson)

Fischer-Bühner (FEM, Germany): ‘Advances in thePrevention of Investment Casting Defects Assistedby Computer Simulation’ and Marco Actis Grande(Turin Polytechnic, Italy): ‘Computer Simulation ofthe Investment Casting Process: Widening of theFilling Step’. Their work concerned carat golds andthey showed how gold alloys behave differently fromsilver (2). There is an urgent need to examine thebehaviour of platinum and palladium alloys in thesemodelling experiments, as their material propertiesare very different from those of gold and silver.

Concluding Remarks The presentations relating to palladium as a jew-

ellery alloy now provide a firm technical

underpinning of this exciting metal and its manufac-ture into jewellery. The technology of platinumjewellery manufacture was also addressed, adding toour already substantial knowledge base. From theseand other standpoints, year 2007 proved to be yetanother excellent vintage for the Santa FeSymposium®. It is an unmissable event for all seriousjewellery manufacturers. The Santa Fe Symposium®

proceedings are published as a book and thePowerPoint® presentations are available onCD-ROM. They can be obtained from the organis-ers (1). The 22nd Symposium will be held once againin Albuquerque, New Mexico, from 18th to21st May 2008.


The ReviewerChristopher Corti holds a Ph.D. in Metallurgyfrom the University of Surrey (U.K.) and iscurrently a consultant for the World GoldCouncil and the Worshipful Company ofGoldsmiths in London. He served as Editor ofGold Technology magazine and currently editsGold Bulletin journal and the Goldsmiths’Company Technical Bulletin. A recipient of the

Santa Fe Symposium® Research Award, Technology Award andAmbassador Award, he is a frequent presenter at the Symposium.

1 The Santa Fe Symposium: http://www.santafesymposium.org/

2 C. W. Corti, Platinum Metals Rev., 2007, 51, (1), 193 ‘Palladium – an introduction’, palladium jewellery

technical manual, Johnson Matthey, New York,2007: http://www.johnsonmattheyny.com/, inpreparation

4 ‘MJSA, World Gold Council Announce Creation ofWhite Gold Whiteness Index’, ManufacturingJewelers and Suppliers of America, press release,15th March, 2005:http://www.mjsa.org/press/press_read.php?id=43

5 ‘What is a White Gold?’, World Gold Council,March, 2005 and references therein: http://www.gold.org/jewellery/technology/colours/white_guide.html

6 J. Maerz, ‘Casting Gold to Platinum’, The 12th SantaFe Symposium on Jewelry ManufacturingTechnology, Albuquerque, New Mexico, 17–20May, 1998, ed. D. Schneller, Met-Chem ResearchInc, 1998, pp. 321–336

7 Official Journal of the European Union,Commission Directive 2004/96/EC, 27 September,2004, EU, 28.9.2004, pp. L 301/51–L 302/52

References


IntroductionThis volume is the first in a series which covers

molecular diversity and combinatorial chemistry,high-throughput discovery and associated technolo-gies including characterisation techniques. Particularareas of interest having relevance to the platinumgroup metals (pgms) have been selected for a seriesof reviews in this Journal. The first of theseappeared in the April 2007 issue (1). Here, KimChandler reviews Chapter 5: ‘A CombinatorialMethod for Optimization of Materials for Gas-Sensitive Field-Effect Devices’, by M. Eriksson, R.Klingvall and I. Lundström (Linköping University,Sweden). Sue Ellis reviews Chapter 7: ‘InfraredThermography and High-Throughput ActivityTechniques for Catalyst Evaluation for HydrogenGeneration from Methanol’, by Eduardo E. Wolf,Stephen Schuyten and Dong Jin Suh (University ofNotre Dame, Indiana, U.S.A.). Ann Keep reviewsChapter 8: ‘New Catalysts for the Carbonylation ofPhenol: Discovery Using High-ThroughputScreening and Leads Scale-Up’, by Donald W.Whisenhunt and Grigorii Soloveichik (GeneralElectric Global Research, U.S.A.); and Sarah Ballreviews Chapter 14: ‘High-Throughput Screeningfor Fuel Cell Technology’, by Jing Hua Liu, Min KuJeon, Asif Mahmood and Seong Ihl Woo (KoreaAdvanced Institute of Science and Technology,South Korea).

Gas-Sensitive Field-Effect DevicesGas-sensitive field-effect devices which incorpo-

rate a thin layer of a pgm such as palladium orplatinum as gate material (the material used in theterminal gate area) have been developed for hydro-gen and ammonia sensing. These devices, fabricatedby semiconductor technology, have been employedin some specialised commercial applications.

The team at Linköping University, Sweden, ledby Professor Ingemar Lundström (one of theauthors of the chapter), has dominated this field formore than thirty years, and is responsible for mostof the impressive work done towards the under-standing and advancement of these devices.Lundström’s team has shown that for catalytic met-als such as palladium, platinum and iridium, boththe type of metal and its morphology (porosity andthickness) play an important role in the sensitivity,stability and selectivity of the sensors.

Chapter 5 begins with a general introduction anda brief history of gas sensors. Surprisingly, no men-tion is made of amperometric (toxic and oxygen) gasdetectors which utilise pgm powders as electrodesand are commercially available and widely used.

This is followed by a simple but useful illustra-tion of the hydrogen sensing mechanism for ametal-insulator-semiconductor (MIS) device. Themodel, proposed by the authors several years ago,suggests that for a thick Pd film, three steps are

“Combinatorial and High-ThroughputDiscovery and Optimization of Catalystsand Materials”CRITICAL REVIEWS IN COMBINATORIAL CHEMISTRY, VOLUME 1EDITED BY RADISLAV A. POTYRAILO (General Electric Global Research Center, New York, U.S.A.) AND WILHELM F. MAIER

(Saarland University, Germany), CRC Press, Boca Raton, U.S.A., 2007, ISBN 978-0-8493-3669-0, £115.00, U.S.$199.95

A Selective Review by Kim Chandler* and Ann Keep**Johnson Matthey, Orchard Road, Royston, Hertfordshire SG8 5HE, U.K.; E-mail: *[email protected];

**[email protected]

and Sue Ellis† and Sarah Ball††

Johnson Matthey Technology Centre, Blounts Court, Sonning Common, Reading RG4 9NH, U.K.; E-mail: †[email protected];††[email protected]

DOI: 10.1595/147106707X238860


involved: hydrogen dissociation on the gate metalsurface, transportation of the hydrogen atomthrough the metal film, and trapping of the hydrogenatom at the metal insulator interface where polaris-ation occurs.

Most of the complicated theory of MIS is omit-ted, so this chapter would most benefit readers whohave field-effect transistor (FET) expertise.However, references for the underlying semiconduc-tor principles – much of which were developed bythe authors – are provided. The focus is on a combi-natorial method for the optimisation of gas sensors,in line with the main theme of the book.

Device performance can be improved by usingtwo catalytic metal layers, each independently opti-mised. The first pgm metal layer is deposited at themetal-insulator interface and the second on top ofthe first. To achieve this using conventional FETsrequires the preparation of large numbers of devices,while overcoming inconsistency between batches.The authors propose a neat and imaginative schemethat sidesteps these issues. By deploying a vacuumdeposition process to vary the thickness of twometal layers independently, in orthogonal directionsacross a single substrate, all possible thickness com-binations over a MIS capacitor device can be created.A scanning light pulse technique is employed whichallows measurements of parameters analogous toFET characteristics at small illuminated pointsacross the MIS substrate. This is used to study thegas response, so as to identify the best composition.

The concept is clearly and effectively demonstrat-ed on a rhodium (first film)/palladium bilayer with athickness of up to around 25 nm. Results from expo-sure to hydrogen and ammonia (separately) are aseries of very striking voltage response images. Areasexhibiting a high hydrogen sensitivity but a lowammonia sensitivity can be clearly identified. So canareas giving a high ammonia response but a lowhydrogen response. Contour plots showing areaswith different sensitivities resulting from exposure todifferent hydrogen concentrations are particularlyvivid.

The application of combinatorial methods in gassensors is at an early stage of progress, so there is lit-tle literature for the authors to relate to. The pgmsplay a fundamental role in FET-based sensors. There

are also brief discussions on the effect of interfer-ence gases and accelerated ageing by heattreatment/annealing, but without inclusion of someof the pertinent values. The section on annealingmight well have been expanded, as annealing appearsto be capable of reversing the sensitivity. Since thedevice is operated at 140ºC, knowing the annealingtemperature and duration would help to ascertainits stability.

It is a little disappointing that there is no confir-matory study to show that the compositionsidentified by the experimental work really showedthe sensitivities and selectivity described whenapplied to conventional FETs. Also most of thematerial was published in late 2005 (Reference 9within the chapter, see (2)). Despite this, the chapteris authoritative and well prepared, albeit rather short– like most of the other chapters. The proposedcombinatorial method is elegant and should pro-mote further work. This chapter is essential readingfor workers in this field and would also benefitscientists interested in material technology or high-throughput techniques.

Hydrogen Generation from MethanolIn Chapter 7, the authors have used hydrogen

generation from methanol as an example to highlightsome of the benefits and weaknesses of applying ahigh-throughput approach to catalyst development.They discuss how high-throughput techniques com-plement standard catalyst screening methods, butacknowledge that they are no substitution for thedetailed work required to gain a thorough under-standing of the reaction and deactivationmechanisms.

The authors start by reminding the readers that,historically, catalyst screening has followed an empir-ical approach. This still prevails to some extent, andthey suggest that progress is normally limited by theamount of time available on test rigs. They proposethat this ‘brute-force’ approach can be improved onby successfully combining high-throughput experi-mentation (HTE) with a knowledge-based catalystdesign, based on a hypothetical reaction model.

In the study presented, infrared thermography isused as an initial screening tool to assess the activityof a range of copper-zinc-palladium catalysts for the


methanol partial oxidation reaction. This reactionhas been studied in detail by many groups as amethod for generating hydrogen to power fuel cells,although the fashion in the fuel cell industry current-ly favours the direct use of methanol or hydrogenfuel source. Nevertheless, the reaction is a usefulillustrative example. While apparently simple, thereare several side reactions that need to be takenaccount of in the interpretation of the HTE results.

The milligram scale thermography tests areacknowledged as a crude first screen, offering noinformation on the kinetics, selectivity or durabilityof the catalysts. The authors rely on the exothermicnature of the chosen reaction, highlighting how thetechnique can only be applied to reactions where ameasurable thermal response (due to reaction oradsorption) can be expected. The HTE tests are fol-lowed up by parallel reactor tests on 1 to 2 g ofmaterial before the most promising samples arestudied in detail, with the kinetic and durabilityresults feeding back to validate and improve theoriginal reaction model.

Unlike other applications where HTE is used, theperformance of a heterogeneous catalyst is depen-dent on a range of subtle factors, over and abovematerial composition, which affect the critical sur-face structure. One aspect that the authors do nothighlight is that for heterogeneous catalysts, the syn-thesis of the materials is often the time consumingstep that cannot be easily addressed by high-throughput techniques.

In summary, the authors illustrate that whileHTE should not be considered as the ‘Holy Grail’ ofcatalysis, if used wisely, it can be a valuable and pow-erful experimental tool.

Palladium-Catalysed Carbonylationof Phenol

In Chapter 8, researchers from General Electric(GE) describe the use of high-throughput experi-ments to optimise the homogeneous palladium-catalysed carbonylation of phenol. This work wascarried out from 1997 onwards. The chapter givesboth an overview of the reaction and detailed exper-imental procedures.

Diphenylcarbonate is a raw material for the man-ufacture of polycarbonates such as Lexan®. It is

currently made in a two-step process: carbonylationof methanol to dimethylcarbonate followed bytransesterification with phenol. A one-step processmight have a lower environmental impact. However,so far, even the best processes for carbonylation ofphenol to diphenylcarbonate suffer from lowturnover numbers and poor rates.

The best catalysts are palladium(II) complexes suchas Pd(acac)2 (acac = acetylacetonato), JohnsonMatthey’s product Pd-70, and Pd(dppb)Cl2 (dppb =1,4-bis(diphenylphosphino)butane), Johnson Matthey’sproduct Pd-105. The GE researchers aimed to improvetheir activity with additives such as other metalcomplexes, bases, ligands and halides. For example,Ce(acac)3, PbO and tetraethylammonium bromideenhance activity. They used arrays of 2 cm3 gaschromatography (GC) vials inside an autoclave at 5to 10 MPa and 100ºC. The results from these high-throughput experiments correlated well withperformance when scaled up 200-fold.

The results showed some complex synergisticeffects when several metal additives were combined.For example, adding iron increases the turnovernumber of a system doped with lead and titaniumfrom 1068 to 1631. These effects were surprisingand would have been difficult to spot using tradi-tional low-throughput methods. The performanceof the Pd-70 catalyst improved from a turnovernumber around 500 to around 7000. GE ran someof the best catalytic systems in a one gallon bench-top continuous reactor and filed extensive patentson the process (3, 4). However, some comment onthe likelihood of scaling up to a commercial processwould have been welcome.

Overall, the chapter gives a comprehensiveaccount of the catalyst screening carried out. Cleargraphs and tables detail the results, along with dis-cussion of the possible reaction mechanism. It waspleasing to see high-throughput methods applied toa long-standing and intractable problem in homoge-neous catalysis. The methods give unique insightsinto possible future ‘cocktail’ catalysts for industrialprocesses.

Fuel Cell TechnologyChapter 14 reviews the different approaches that

have been applied to date to high-throughput


screening of fuel cell electrocatalysts. Four differentscreening techniques are discussed: optical, electro-chemical, scanning electrochemical and infra-red(IR) thermography. Examples are given for eachtechnique, including types of catalyst array, method-ologies for deposition of catalyst formulations,suitability of the techniques and their limitations.

Optical screening using fluorescence is describedas a coarser technique, useful for arrays with widecompositional variations, but with some limitationsin sensitivity. Electrochemical and scanning electro-chemical microscopy techniques allow greateraccuracy and flexibility, with possibilities to vary theelectrolyte, solution and reactants, as well as the cat-alyst formulations studied. The examples used withinthe chapter cover the electrochemical reactions ofoxygen reduction and evolution, methanol oxidationand hydrogen oxidation in the presence of carbonmonoxide (CO) impurities. The techniquesdescribed can be used to give information on reac-tion pathways and the effects of catalyst particle sizeon catalytic activity, as well as the variation in activi-ty with catalyst formulation. IR thermographyscreening is also described, as a method to determinethe gas phase activity of transition and base metaloxide-doped platinum on carbon catalysts forremoval of impurities such as CO under fuel celloperating conditions.

The review would be useful for those requiringan introduction to the variety of rapid screeningtechniques available for fuel cell catalysts. Referencesare made to a range of relevant literature papers cov-ering different types of catalyst array, data analysistechniques, and findings regarding improved catalystformulations for methanol oxidation and oxygenreduction and evolution. A familiarity with the fuelcell reactions within proton exchange membranefuel cell (PEMFC) and direct methanol fuel cell(DMFC) is assumed. Figures within the chapter arewell chosen to illustrate the principles behind the dif-ferent types of screening techniques and methods ofplotting activity data for complex ternary, quaternaryand even quinternary catalyst compositions.

All examples discussed relate to pgm-containingcatalysts, in particular platinum and ruthenium,reflecting the current requirement for these metalswithin PEMFC and DMFC catalysts. However,

combinatorial techniques are described as offering aclear opportunity to rapidly screen a wide range ofcatalyst formulations containing pgm and non-pgmelements, with a view to reducing catalyst costs with-out compromising activity.

Generally the catalyst materials described havebeen prepared by techniques such as thin film sput-tering and dispensing of metal solutions to producemicrodots, followed by a reduction or heat treatmentstep. These methods use small amounts of materialsand allow a wide compositional range to be studiedrapidly. Little comment is made on attempts toreproduce the most active catalyst formulations at alarger scale, and to verify the predictions made byrapid screening in operational fuel cell systems. Asrapid screening techniques have only recently beenapplied in the area of fuel cell catalysis, the prepara-tion and validation of active formulations fromcombinatorial studies at larger scales will still be inprogress at this time.

Concluding RemarksThe chapters reviewed in Platinum Metals Review

here and in a previous issue (1) cover some of therange of industrial applications of relevance to thepgms which have been studied using combinatorialand high-throughput techniques. These include datastorage materials and technology (1), gas-sensitivefield-effect devices, catalyst development for hydro-gen generation and for the carbonylation of phenol,and fuel cell electrocatalyst technology.

A further review of the entire book:“Combinatorial and High-Throughput Discoveryand Optimization of Catalysts and Materials” can beread in Reference (5).

References1 D. M. Newman and M. L. Wears, Platinum Metals Rev.,

2007, 51, (2), 932 R. Klingvall, I. Lundström, M. Löfdahl and M.

Eriksson, IEEE Sens. J., 2005, 5, (5), 9953 K. V. Shalyaev, G. L. Soloveichik, D. W. Whisenhunt

Jr. and B. F. Johnson, General Electric, U.S. Patent6,440,892; 2002

4 K. V. Shalyaev, B. F. Johnson, D. W. Whisenhunt Jr.and G. L. Soloveichik, General Electric, U.S. Patent6,440,893; 2002

5 O. Trapp, Angew. Chem. Int. Ed., 2007, 46, (12), 1943

PROPERTIESPlatinum-Catalyzed High Temperature Oxidationof MetalsQ. DONG, G. HULTQUIST, G. I. SPROULE and M. J. GRAHAM,Corros. Sci., 2007, 49, (8), 3348–3360

Al, Cr, Ni and Zr were sputter-coated with porousPt films (1). SIMS analysis on partly Pt-coated metalsamples at different oxide depths in areas with Pt andin areas away from Pt indicated an enhanced inwardoxide growth in the Pt area and at mm-ranged dis-tance from the Pt area. Weight gain measurements onPt-coated Ni samples showed a reduced or increasedoxidation rate depending on the amount of (1).

SERS at Structured Palladium and PlatinumSurfacesM. E. ABDELSALAM, S. MAHAJAN, P. N. BARTLETT, J. J.BAUMBERG and A. E. RUSSELL, J. Am. Chem. Soc., 2007, 129,(23), 7399–7406

Templated electrodeposition through colloidal tem-plates was used to produce thin (< 1 μm) films (1) ofPt- and Pd-containing close packed hexagonal arraysof uniform sphere segment voids. The SERS spectrafor benzenethiol adsorbed on the surfaces of (1) withdifferent thicknesses and void diameters are reported.For 633 nm radiation, enhancement factors of 550and 1800 can be obtained for Pt and Pd, respectively.

Martensitic Transformation in TiPd Shape MemoryAlloys Studied by PAC Method with 181Ta ProbesA. KULINSKA and P. WODNIECKI, Intermetallics, 2007, 15, (9),1190–1196

The perturbed angular correlation method wasapplied to study the martensitic phase transition ofthe title alloy doped with 181Hf/181Ta probe atoms.Strong dependences of the martensite start tempera-ture (MS) and the shape of the hysteresis loop (TH) onthe small admixture of the Hf impurities in TiPdcompound were found. The observed decrease of theMS value differs from the behaviour of TiNi, whereadding Hf as the third element leads to a rise of MS.

Deformation Tracks Distribution in Iridium SingleCrystals Under TensionP. PANFILOV, J. Mater. Sci., 2007, 42, (19), 8230–8235

The deformation tracks distribution in a single crys-tal of f.c.c.-Ir (1), which exhibits cleavage afterconsiderable elongation, is considered. Octahedralslip is the sole deformation mechanism in (1) at roomtemperature. In contrast to other f.c.c.-metals, theresource of plasticity of (1) is exhausted at the ini-tial/early stages of plastic deformation, when theoctahedral slip bands are homogeneously distributedon the working surface and necking is absent in thevicinity of the dangerous crack.

CHEMICAL COMPOUNDSSelf-Assembly of a Nanoscopic Platinum(II)Double Square CageS. GHOSH, S. R. BATTEN, D. R. TURNER and P. S. MUKHERJEE,Organometallics, 2007, 26, (13), 3252–3255

A rigid tripodal ligand (1) with an ester cap (1 =1,1,1-tris(4-pyridyl)COOR, where R = PhCH(C2H5))was designed and prepared. A 2:3 self-assembly of (1)with cis-(PEt3)2Pt(OTf)2 as a 90º ditopic acceptor unityielded an unusual 3D cage (2). Multinuclear NMRspectroscopy and single-crystal structure analysiswere used to characterise (2).

Nickel(II), Palladium(II) and Platinum(II)Complexes of N-Allyl-N'-pyrimidin-2-ylthioureaS. S. KANDIL, S. M. A. KATIB and N. H. M. YARKANDI, TransitionMet. Chem., 2007, 32, (6), 791–798

The title complexes with N-allyl-N'-pyrimidin-2-yl-thiourea (1) were synthesised in 1:1 and 1:2 [metal:ligand]stoichiometric ratios. The 1H- and 13C- NMR chemicalshifts revealed coordination of one pyrimidine-N and Satoms to Pt(II) and Pd(II). The IR spectra indicated (1)acts as a bidendate ligand towards Pt(II) and Pd(II), andcoordinates via thione-S and a pyrimidine-N.

Synthesis and X-ray Structures of Water-SolubleTris(hydroxymethyl)phosphine Complexes ofRhodium(I)F. LORENZINI, B. O. PATRICK and B. R. JAMES, Dalton Trans.,2007, (30), 3224-3226

H2O-soluble Rh(I) complexes: RhCl(1,5-cod)(THP)(1), [Rh(1,5-cod)(THP)2]Cl (2), RhCl(THP)4 (3), andtrans-RhCl(CO)(THP)2 (4) (THP = P(CH2OH)3) havebeen synthesised and characterised. (1), (2) and (3) arereported to be the first potentially useful entries intoRh(I)-THP chemistry, while (1) and (4) are the firststructurally characterised Rh(I)-THP complexes.

PHOTOCONVERSIONHighly Phosphorescent Perfect Green EmittingIridium(III) Complex for Application in OLEDsH. J. BOLINK, E. CORONADO, S. GARCIA SANTAMARIA, M.SESSOLO, N. EVANS, C. KLEIN, E. BARANOFF, K. KALYANASUNDARAM,M. GRAETZEL and MD. K. NAZEERUDDIN, Chem. Commun.,2007, (31), 3276–3278

Bis-(2-phenylpyridine)(2-carboxy-4-dimethylamino-pyridine)iridium(III) (N984) was synthesised byreacting [Ir(ppy)2(Cl)]2 with methyl-dimethylamino-picolinate and Na2CO3 in 2-ethoxyethanol. A solutionprocessable OLED device incorporating the yellowN984 complex displays electroluminescence spectrawith a narrow bandwidth of 70 nm at half of its inten-sity, with colour coordinates that are very close to thePAL standard for a green emitter.


ABSTRACTSof current literature on the platinum metals and their alloys

DOI: 10.1595/147106707X239698

Platinum Metals Rev., 2007, 51, (4)

Periodic Mesoporous Silica having CovalentlyAttached Tris(bipyridine)ruthenium Complex:Synthesis, Photovoltaic andElectrochemiluminescent PropertiesJ. FONT, P. DE MARCH, F. BUSQUÉ, E. CASAS, M. BENITEZ, L.TERUEL and H. GARCÍA, J. Mater. Chem., 2007, 17, (22),2336–2343

A tris(bpy)Ru derivative with two terminal tri-ethoxysilyl groups attached to one of the bpy ligandswas used with TEOS for the preparation of atris(bpy)Ru-containing mesoporous silica (1), usingCTABr as a structure-directing agent. The tris(bpy)Ruat the walls in (1) gives its orange coloration. (1) exhibitsphotovoltaic (VOC = 140 mV, ISC = 2.6 μA) and elec-trochemiluminescence activity (λmax = 610 nm).

SURFACE COATINGSPlasma-Enhanced Atomic Layer Deposition ofPalladium on a Polymer SubstrateG. A. TEN EYCK, S. PIMANPANG, J. S. JUNEJA, H. BAKHRU, T.-M. LU and G.-C. WANG, Chem. Vap. Deposition, 2007, 13, (6–7),307–311

Pd has been deposited on air-exposed, annealedpoly(p-xylylene) (PPX) at 80ºC using a remote, induc-tively coupled, H2/N2 plasma with Pd(hfac)2 as theprecursor. By optimising the mixture of H2 and N2,the PPX surface is modified to introduce active sitesallowing the chemisorption of the Pd(hfac)2. In addi-tion, enough free H atoms are available at the surfacefor ligand removal and Pd reduction, while at thesame time, enough H atoms are consumed in theplasma to ensure there is no degradation of the PPX.

APPARATUS AND TECHNIQUEClassification of Multiple Defect Concentrations inWhite Wine by Platinum Microelectrode VoltammetryL. FRANCIOSO, R. BJORKLUND, T. KRANTZ-RÜLCKER and P.SICILIANO, Sens. Actuators B: Chem., 2007, 125, (2), 462–467

Concentrations of defect pairs added to a whitewine were classified by voltammetric measurementson interdigitated Pt microelectrodes using principalcomponent analysis of the current responses.Ascorbic acid/acetaldehyde, ascorbic acid/SO2 andacetaldehyde/SO2 combinations of 0, 1, 2 and 3 mMconcentrations were investigated.

Amperometric Glucose Biosensor Based onElectrodeposition of Platinum Nanoparticles ontoCovalently Immobilized Carbon Nanotube ElectrodeX. CHU, D. DUAN, G. SHEN and R. YU, Talanta, 2007, 71, (5),2040–2047

A fabricated GOx/Aunano/Ptnano/CNT electrode(1) was covered with a thin layer of Nafion to avoidthe loss of GOx (glucose oxidase) and to improve theanti-interferent ability. (1) exhibited rapid responsefor glucose in the absence of a mediator. The biosen-sor based on (1) had good reproducibility and stabilityfor the determination of glucose.

Preparation and Characterisation of Palladium-Loaded Polypropylene Porous Hollow FibreMembranes for Hydrogenation of DissolvedOxygen in WaterR. VAN DER VAART, V. I. LEBEDEVA, I. V. PETROVA, L. M.PLYASOVA, N. A. RUDINA, D. I. KOCHUBEY, G. F. TERESHCHENKO,V. V. VOLKOV and J. VAN ERKEL, J. Membrane Sci., 2007, 299,(1–2), 38–44

Pd could be deposited on a hydrophobic porousAccurel polypropylene membrane hollow fibre, whilekeeping its hydrophobic nature. Pd loadings as low as0.36% (w/w) were sufficient to catalyse the hydro-genation of dissolved O2 while maintaining diffusionlimited kinetics. A fast O2 removal system wasobtained that has the potential of maintainingremoval rate, even at very low concentrations of O2.

HETEROGENEOUS CATALYSISEffect of Palladium on Sulfur Resistance in Pt–PdBimetallic CatalystsH. JIANG, H. YANG, R. HAWKINS and Z. RING, Catal. Today,2007, 125, (3–4), 282–290

The interactions of H2 and H2S with Pt-Pd bimetal-lic catalysts (1) were studied using DFT. Whenalloying the Pt catalyst with a small amount of Pd at aparticular surface atomic ratio range, the adsorptionsof both H2 and H2S were enhanced, but the adsorp-tion energy of H2 increased more than that of H2S.The desorption energy of H2 from Pt or Pd, as well asof (1) supported on a zeolite, were calculated by TPD;these values were compared against the DFT resultsto explain why (1) has better S resistance than Pt.

The Effect of Ionic Liquid in Supported IonicLiquid Catalysts (SILCA) in the Hydrogenation ofα,β-Unsaturated AldehydesP. VIRTANEN, H. KARHU, K. KORDAS and J.-P. MIKKOLA, Chem.Eng. Sci., 2007, 62, (14), 3660–3671

Pd nanoparticles/ionic liquid layer/active C clothSILCAs (1) were successfully employed in two differ-ent hydrogenation processes. Leaching of both Pdand ionic liquids was found to be negligible, and notthe reason for slow deactivation of (1). The ionic liq-uid layer residing on the support of (1) can eitherenhance the reaction rate or affect the selectivity pro-file of the reaction.

Palladium Ethylthioglycolate Modified Silica–ANew Heterogeneous Catalyst for Suzuki and HeckCross-Coupling ReactionsM. AL-HASHIMI, A. C. SULLIVAN and J. R. H. WILSON, J. Mol.Catal. A: Chem., 2007, 273, (1–2), 298–302

A silica-supported S-containing ethylthioglycolatematerial that readily binds Pd from solutions ofPd(OAc)2 was synthesised. This affords an active andrecyclable solid phase catalyst (1). Close to quantita-tive conversions were observed with (1) for Suzukireactions in less than 2 h. The Heck reactions werecomplete within 24 h.

209

Platinum Metals Rev., 2007, 51, (4)

Effect of Liquid Property on Adsorption andCatalytic Reduction of Nitrate over Hydrotalcite-Supported Pd-Cu CatalystY. WANG, J. QU and H. LIU, J. Mol. Catal. A: Chem., 2007, 272,(1–2), 31–37

Nitrate ions were adsorbed by Pd-Cu/hydrotalcite(1) at 10, 25 and 35ºC. Higher reaction temperatureaccelerated nitrate adsorption and reduction, andsimultaneously decreased the accumulation of NO2

–

and NH4+. pH and coexisted ions in the H2O also

showed influence on nitrate removal. The activity of(1) was maintained after repeated use.

Combining Diffuse Reflectance InfraredSpectroscopy (DRIFTS), Dispersive EXAFS, andMass Spectrometry with High Time Resolution:Potential, Limitations, and Application to theStudy of NO Interaction with Supported Rh CatalystsM. A. NEWTON, A. J. DENT, S. G. FIDDY, B. JYOTI and J. EVANS,Catal. Today, 2007, 126, (1–2), 64–72

The title experiment was used to study the oxidation(by NO) and reduction (by H2) of Rh/γ-Al2O3. Thespecific role that the linear NO+ species has in bothoxidation and reduction of Rh, and the role it may playreactively at elevated temperatures were determined.New information was gained about the physical char-acter of the linear NO+ species and the nature of theRh phase/sites with which it is associated.

HOMOGENEOUS CATALYSISPhosphine Oxides as Stabilizing Ligands for thePalladium-Catalyzed Cross-Coupling of PotassiumAryldimethylsilanolatesS. E. DENMARK, R. C. SMITH and S. A. TYMONKO, Tetrahedron,2007, 63, (26), 5730–5738

The Pd-catalysed cross-coupling reaction of potas-sium (4-methoxyphenyl)dimethylsilanolate with arylbromides has been achieved using Ph3P(O) as a sta-bilising ligand. Allylpalladium(II) chloride dimer wasemployed as a precatalyst. Unsymmetrical biarylswere prepared from a variety of aryl bromides in goodyield with short reaction times.

Catalysts Based on Palladium DendrimersR. ANDRÉS, E. DE JESÚS and J. C. FLORES, New J. Chem., 2007,31, (7), 1161–1191

The advances in Pd-catalysed reactions using den-drimer-based catalysts are reviewed. This includes therole of Pd dendrimers as: (a) soluble macromoleculesfor the support of catalysts, that are separable bynanofiltration techniques; (b) ligand-modifiers thatcan tune the solubility of the catalyst; (c) spacers forcatalyst immobilisation on silica or polymers; and (d)precursors for the synthesis of mono- and bimetallicnanoparticles of controlled size and narrow size dis-tribution. Examples of catalysis with related metalsystems, such as star-shaped molecules or hyper-branched polymers, are also included. (169 Refs.)

Pd–Smopex-111: A New Catalyst for Heck andSuzuki Cross-Coupling ReactionsX. JIANG, J. SCLAFANI, K. PRASAD, O. REPIC and T. J.BLACKLOCK, Org. Process Res. Dev., 2007, 11, (4), 769–772

Pd was loaded onto Smopex-111 by stirring a pre-filtered toluene solution of Pd(OAc)2 andSmopex-111 heated to 70ºC. After filtration and wash-ing, the complex was dried to give Pd-Smopex-111 (1)with a Pd loading of 4.4–4.7 wt.%. (1) was a highlyactive catalyst for Heck and Suzuki cross-couplingreactions. Both electron-donating and electron-with-drawing groups on the aryl bromide were tolerated. (1)is recyclable with no noticeable change in activity.Isolation of (1) involves simple filtration.

A Convenient Catalyst System for MicrowaveAccelerated Cross-Coupling of a Range of ArylBoronic Acids with Aryl ChloridesM. L. CLARKE, M. B. FRANCE, J. A. FUENTES, E. J. MILTON andG. J ROFF, Beilstein J. Org. Chem., 2007, 3, 18

A readily prepared, air-stable Pd precatalyst derivedfrom the amine-phosphine ligand, dcpmp, promotedSuzuki cross-coupling between activated aryl chlo-rides and a range of boronic acids under microwaveheating conditions. High yields of the product biarylswere obtained in 15 min or less. Heavily fluorinatedboronic acids do not participate in these Suzuki cou-plings due to protodeboronation.

Catalytic Hydrogenation of Nitrile Rubber UsingPalladium and Ruthenium ComplexesG. A. S. SCHULZ, E. COMIN and R. F. DE SOUZA, J. Appl. Polym.Sci., 2007, 106, (1), 659–663

The hydrogenation of acrylonitrile-butadienecopolymer (NBR) using Pd(OAc)2 or RuCl2(PPh3)3

catalysts has been investigated in order to produce atotally saturated nitrile rubber. The hydrogenation ofNBR is effective with both catalysts and under theappropriate conditions total conversion to HNBR isachievable. Pd(OAc)2 requires harsher reaction condi-tions and has the drawback of gel formation underhigh conversion. The degree of hydrogenation wasdetermined by IR and NMR spectroscopy.

Hydroformylation of Higher Olefin in Halogen-Free Ionic Liquids Catalyzed by Water-SolubleRhodium–Phosphine ComplexesQ. LIN, W. JIANG, H. FU, H. CHEN and X. LI, Appl. Catal. A:Gen., 2007, 328, (1), 83–87

The biphasic hydroformylation of higher olefinswas carried out in 1-n-alkyl-3-methylimidazolium p-toluenesulfonate using Rh-TPPTS complexes as thecatalyst. High activity and chemoselectivity for alde-hyde with retention of the catalyst in the ionic liquidphase was exhibited. The ionic liquid containing cata-lyst can be easily separated and reused. The reactionrate is dependent on the cation and anion of the ionicliquids used. Furthermore, the reaction rate was accel-erated when the chain length of the alkyl in the ionicliquids was comparable with that of the olefin.

210

FUEL CELLSCombinatorial Electrochemical Cell Array for HighThroughput Screening of Micro-Fuel-Cells andMetal/Air BatteriesR. JIANG, Rev. Sci. Instrum., 2007, 78, (7), 072209

An electrochemical cell array (1) was designed thatcontains a common air electrode and 16 microanodesfor high-throughput screening of both fuel cells(based on PEM) and metal/air batteries. Electrodematerials were coated on the anodes of the electro-chemical cell array and screened by switching agraphite probe from one cell to the others. (1) wasused to study DMFCs, including high-throughputscreening of electrode catalysts involving Pt and Ru,and determination of optimum operating conditions.

Catalysts for Direct Ethanol Fuel CellsE. ANTOLINI, J. Power Sources, 2007, 170, (1), 1–12

The electrocatalysts which have been tested asanode and cathode materials for DEFCs arereviewed, with attention focused on the catalyst com-position, degree of alloying, presence of oxides andactivity for the EtOH oxidation reaction. Converselyto the MeOH oxidation reaction, the best binary cat-alyst for EtOH oxidation in acid environment is notPt-Ru but Pt-Sn. Ternary Pt-Ru- and Pt-Sn-basedelectrocatalysts are also described. Pt-Pd (9:1) showedhigher EtOH tolerance than Pt when used as cathodematerial. (90 Refs.)

Carbon Nanotubes Supported Pt-Ru-Ni asMethanol Electro-Oxidation Catalyst for DirectMethanol Fuel CellsF. YE, S. CHEN, X. DONG and W. LIN, J. Nat. Gas Chem., 2007,16, (2), 162–166

Pt-Ru/CNTs and Pt-Ru-Ni/CNTs catalysts wereprepared by reduction of metal precursors withNaBH4 at room temperature. The particle size of thePt-Ru-Ni/CNTs catalyst is ~ 4.8 nm. The catalyticactivity and stability for MeOH electrooxidation weremeasured by electrochemical impedance spec-troscopy, linear sweep voltammetries, andchronoamperometry. The catalytic activity and stabil-ity of the Pt-Ru-Ni/CNTs catalyst are higher thanthose of the Pt-Ru/CNTs catalyst.

Pt and Ni Carbon Nitride Electrocatalysts for theOxygen Reduction ReactionV. DI NOTO, E. NEGRO, R. GLIUBIZZI, S. GROSS, C. MACCATOand G. PACE, J. Electrochem. Soc., 2007, 154, (8), B745–B756

A precursor (1) was prepared from a Pt chloride anda Ni cyanometallate complex in the presence ofsucrose, which acts as an organic binder. The thermaldecomposition of (1), which was studied at400–700°C, and the procedure for activating theproducts, were critical. The electrochemical efficiencyin the O reduction reaction of the title electrocatalystsproved to be much higher than that of standard mate-rials having a similar Pt content.

MEDICAL USESTwo Different Types of Age-Hardening Behaviorsin Commercial Dental Gold AlloysK. HISATSUNE, T. SHIRAISHI, Y. TAKUMA, Y. TANAKA and R. H.LUCIANO, J. Mater. Sci.: Mater. Med., 2007, 18, (4), 577–581

Age-hardening behaviour during continuous heat-ing in the title alloys was studied by means ofelectrical resistivity measurements, hardness tests andXRD. Two distinguishable behaviours were found.The difference was attributed to the amount of Pt,and the atomic ratio of Au and Cu in each alloy. Thephase transformations during continuous heatingprogressed in two stages. Increase of the Pt additionin the alloys retards the rate of the reaction anddecreases the amount of the first stage.

Hardening and Overaging Mechanism of aCommercial Au–Ag–Cu–Pd Dental AlloyH.-I. KIM, G.-H. JEON, S.-J. YI, Y. H. KWON and H.-J. SEOL, J. AlloysCompd., 2007, 441, (1–2), 124–130

The ageing behaviour and age-hardening of the titlealloy (1) with small amounts of Pt, Zn and Ir (48.0wt.% Au-32.5 wt.% Ag-8.0 wt.% Cu-7.4 wt.% Pd-2.0wt.% Pt-2.0 wt.% Zn-0.1 wt.% Ir) was investigated.(1) showed apparent age-hardenability at the ageingtemperature of 400ºC. By ageing, the hardness of thesolution-treated specimen began to increase andreached a maximum value, and then the hardnessdecreased continuously by further ageing.

Guanine Binding to Dirhodium TetracarboxylateAnticancer Complexes: Quantum ChemicalCalculations Unravel an Elusive MechanismD. V. DEUBEL and H. T. CHIFOTIDES, Chem. Commun., 2007,(33), 3438–3440

The mechanism of guanine binding to dirhodiumtetracarboxylates, representing an emerging class ofmetal–metal-bonded antitumour complexes, has beenestablished. Numerous experiments led to the charac-terisation of the reactants and products, but thereaction mechanism had not been established. High-level quantum chemical calculations suggest amultiple-step mechanism via an axial Gua-N7 adductand an ax–eq carboxylate chelate as unexpected keyintermediates.

Synthesis, Characterization and AntimalarialActivity of New Iridium–Chloroquine ComplexesM. NAVARRO, S. PEKERAR and H. A. PÉREZ, Polyhedron, 2007,26, (12), 2420–2424

Chloroquine base (CQ) reacted with [Ir(COD)Cl]2

and IrCl3·3H2O to give Ir(CQ)Cl(COD) (1) andIr2Cl6(CQ)·3H2O (2), respectively. Reaction of[Ir(COD)Cl]2 with CQ in the presence of NH4PF6

gave [Ir(CQ)(Solv)2]PF6 (3). Complexes (1)–(3) wereevaluated in vitro against Plasmodium beghei.Comparison of the IC50 values obtained with com-plexes (1)–(3) with that for chloroquine diphosphateindicated a higher activity for (2), while (1) and (3)showed a similar and lower activity, respectively.


ELECTRODEPOSITION AND SURFACECOATINGSPalladium Activator for Plating on PlasticHANGZHOU ORIENTAL MET. FINISHING TECHNOL. CO LTD

Chinese Appl. 1,936,097Plastic can be activated for plating using an activator

containing (in g l–1): 0.05–10 Cu(I) salt; 0.05–2 Pd(II)compound; 2.5–200 Sn; plus 35% HCl 50–800 ml l–1.The steps followed are: deoiling, cleaning, roughening,cleaning, activating at 10–70ºC for 0.5–10 min, clean-ing, treating with a basic solution containing Cu ions,then plating. The process is claimed to be simple, sta-ble and environmentally friendly. The activator isclaimed to have high activity.

APPARATUS AND TECHNIQUEIgnition Device with Iridium-Based Firing TipFEDERAL MOGUL IGNITION UK LTD

European Appl. 1,782,513An ignition device such as a spark plug for an inter-

nal combustion engine includes centre and groundelectrodes, at least one of which includes a firing tipformed from an Ir alloy. The alloy contains (in wt.%):1–3 Rh, 0.1–0.5 W, 0.01–0.05 Zr, preferably ~ 2 Rh,~ 0.3 W, ~ 0.02 Zr, with the balance Ir. The groundelectrode firing tip may alternatively be made from Ptor a Pt alloy.

Microchannel Apparatus with Platinum AluminideVELOCRYS INC World Appl. 2007/047,373

A microchannel reactor or separator contains atleast one microchannel defined by a wall coated withPtAl, with optionally a layer of Al2O3 and one of cat-alytic or sorbent material. The PtAl layer may be apost-assembly coating, and the reactor or separatormade by laminating together sheets. Pt may be coat-ed by electroless plating. A reaction may be carriedout by passing a reactant into the microchannel toform at least one product; if the reactant is a hydro-carbon then the reactor can be used to effecthydrocarbon steam reforming. Essentially no coke isformed in the microchannel.

Adsorption of VOCs Including EthyleneJOHNSON MATTHEY PLC World Appl. 2007/052,074

Pd-doped ZSM-5 (1) is used to adsorb volatileorganic compounds such as C2H4, HCHO orCH3CO2H from perishable organic matter whichmay include foods such as fruit or vegetables, horti-cultural produce such as cut flowers or plants, orrefuse. (1) may be incorporated into a storage con-tainer, package or label and may be used with a VOCindicator. The used (1) can be regenerated for furtheruse by heating to 250ºC for 30 min in air to releasethe adsorbed VOCs. Ratio of Si:Al in the ZSM-5 is≤ 100:1, preferably 22:1–28:1; and Pd content is0.1–10.0 wt.%, preferably 0.5–5.0 wt.%.

Osmium-Based Oxygen SensorW. B. CARLSON et al. U.S. Appl. 2007/0,105,235

A luminescent Os complex [Os(II)(N–N)2L-L]2+

2A– or A2– (1), where N–N is a 1,10-phenanthrolineligand; L-L is cis-1,2-bis(diphenylarseno)ethylene orcis-1,2-bis(diphenylphosphino)ethylene; and A is acounter ion; plus an O2 permeable host material, isused in a pressure sensitive paint. The pressure of anO2-containing fluid flowing over an aerodynamic sur-face, such as an aircraft part, can be measured byilluminating the coated surface to cause luminescenceof (1), then measuring the luminescent intensity.

Ruthenium-Containing BiosensorNATL. YUNLIN UNIV. SCI. U.S. Appl. 2007/0,095,664

A biosensor includes an extended gate field-effecttransistor structure which has a metal oxide semicon-ductor field-effect transistor and at least one sensingunit, with a Ru-containing layer as a sensor, connect-ed by a metal wire. The Ru-containing film is chosenfrom Ru oxide or RuN and is coated onto the extend-ed gate region substrate by radio frequencysputtering. The sensor system can be used for mea-suring pH of solutions or in a vitamin C biosensor.

Platinum-Gold Gas Sensor ElectrodesDELPHI TECHNOL. INC U.S. Patent 7,241,477

A method for forming a PtAu alloy electrode foruse in a gas sensor includes combining Pt and Au pre-cursors to form an electrode ink, forming the ink intoan electrode precursor, firing and treating in an envi-ronment of ≤ 500 ppm O2 to produce an electrodewith an exposed surface Au concentration ≥ 6 timesthe bulk Au concentration. The electrode ink contains(in wt.%): 43–62 Pt, 0.05–1 Au and 38–48 fugitivematerial, plus optionally 2–8 oxides.

HETEROGENEOUS CATALYSISIridium Catalyst for Methane-Containing Waste GasOSAKA GAS CO LTD European Appl. 1,790,412

A catalyst for removing hydrocarbons from combus-tion exhaust gas containing CH4 and excess O2

contains Ir plus Pt, Pd, Rh and/or Ru, supported onZrO2, and has specific surface area 2–60 m2 g–1. Ir ispresent in 0.5–20 wt.%, preferably 1–5 wt.%, relativeto ZrO2. Where Pt is used, it is present in 2–100 wt.%,preferably 5–50 wt.%, relative to Ir. Alternatively or inaddition to Pt, elements Pd, Rh and/or Ru may be pre-sent in 0.5–10 wt.%, preferably 1–5 wt.%, relative to Ir.

Zoned Oxidation Catalyst for Exhaust SystemJOHNSON MATTHEY PLC World Appl. 2007/077,462

An exhaust system for a lean-burn internal combus-tion engine includes a catalyst for oxidising CO andhydrocarbons. A flow-through substrate monolithsupports three washcoat zones each containing atleast one metal selected from Pt, Pd, Rh and Ir,preferably Pt. Metal loadings in each washcoat zoneare (in g ft–3): 10–240 in the first, 5–30 in the secondand 10–120 in the third; 25–390 total metal loading.

212Platinum Metals Rev., 2007, 51, (4), 212–214

DOI: 10.1595/147106707X237078

NEW PATENTS


Dry Impregnation of Platinum on Carbon SubstrateUNIV. ILLINOIS U.S. Appl. 2007/0,105,007

A method of preparation for particles of a metalselected from Pt, Pd, Rh, Ru, Ir, Os, Sn or Cu, prefer-ably Pt, supported on a C substrate such as C black isclaimed. An aqueous solution of metal complex in avolume of H2O not exceeding the pore volume of theC substrate is contacted with the substrate, allowed toabsorb, then heated under reducing conditions toform particles. The pH of the solution is adjusted ifnecessary to < 2 and the Pt-loaded substrate is heat-ed to 200–300ºC. Particles have diameter 15–25 Åand Pt is highly dispersed, at least 120 m2 Pt g–1 Pt,with Pt loadings ≥ 20%.

Carbon Monoxide CatalystA. CHIGAPOV et al. (FORD GLOBAL TECHNOL. LLC)

U.S. Appl. 2007/0,129,247A low-temperature selective CO oxidation catalyst

contains 1–20 wt.% Pt and 1–30 wt.% Co, and has> 90% conversion efficiency at ≤ 140ºC. Alternativelythe catalyst may contain 1–10 wt.% Pt and 1–4 wt.%Co and have conversion efficiency > 50% at 22–33ºC.The weight ratio of Pt:Co is between 1:2–4:1.Applications may include removal of CO from H2-richgas for fuel cells, from exhaust gas during cold-start ofdiesel or petrol engines, or for air purification systemsfor spaces such as tunnels, underground railways,multi-storey carparks or submarines.

Iridium Catalyst for Hydrazine DecompositionKOREA AEROSPACE RES. INST. U.S. Appl. 2007/0,167,322

An Ir catalyst is claimed which has high crushstrength and can be used for hydrazine decomposi-tion for spacecraft and satellite propulsion. Bauxite iscontacted with 0.1–10 M acid solution for 10–14 h;the mixture is filtered; the filtered bauxite is thermal-ly treated by contacting with air at 500–700ºC for2–6 h, then loaded with Ir from a solution containingIrCl3, Ir[(NH3)5Cl]Cl2, H2IrCl6 or Ir(NH3)6Cl3. Theloading step may be repeated 10–20 times to give anIr loading of 30–35 wt.% relative to bauxite. In a finalstep, the catalyst is reduced.

Exhaust Gas Purifying CatalystMAZDA MOTOR CORP U.S. Patent 7,235,511

A catalyst includes a carrier and a catalyst layerwhich includes a noble metal on active Al2O3, Rh car-ried on an O storage agent, Rh carried on Al2O3

coated with ZrO2 and a binder material. The O stor-age agent may be a CeO2-ZrO2-Nd2O3 composite.

Shift Reaction CatalystNISSAN MOTOR CO LTD Japanese Appl. 2007-007,531

A water gas shift reaction catalyst includes Pt, Ce andCu and is prepared by mixing a Pt catalyst powdercontaining Ce, with a Cu catalyst powder. Thecomposition may further include Ti, Zr, V, Nb or Ta.The components are present in (mg ml–1 by catalystunit volume): 0.1–20 Pt, 50–500 Ce and 0.1–80 Cu. Cuis 0.1–10 mass% vs. Pt. The support is an inorganicoxide of Si, Al, Ti, Ce or Zr.

HOMOGENEOUS CATALYSISSynthesis of Aryloctanoyl Amide CompoundsNOVARTIS AG British Appl. 2,431,652

An alternative synthesis of (2S, 4S, 5S, 7S)-2,7-dialkyl-4-hydroxy-5-amino-8-aryloctanoyl amide derivativesor pharmaceutically acceptable salts thereof, in particularaliskiren, uses a Pd-catalysed coupling reaction. Novelcompounds used as intermediates in the synthesis ofthe target compounds are also claimed.

Ruthenium Metathesis CatalystsMATERIA INC World Appl. 2007/075,427

Ruthenium alkylidene complexes having an N-heterocyclic carbene ligand with a 5-memberedheterocyclic ring containing at least one phenyl-substituted N atom bonded directly to a carbenic Catom are claimed. The complexes can be used ascatalysts for olefin metathesis reactions, in particularfor preparation of tetra-substituted cyclic olefins byring closing metathesis.

Hydrogenation ProcessDAVY PROCESS TECHNOL. LTD U.S. Appl. 2007/0,142,679

A continuous homogeneous process for hydrogena-tion of dicarboxylic acids and/or anhydrides uses acatalyst containing Ru, Rh, Os, Pd or Fe, preferablyRu, with an organic phosphine, preferably a tridentatephosphine. Products may include butanediol, THFand/or γ-butyrolactone from fumaric acid or maleicor succinic acid or anhydride. The process is carriedout in the presence of ≥ 1 wt.% H2O, at 500–2000psig and 200–300ºC, so that ~ 1–10 mol H2(g) are usedto strip 1 mol product from the reactor. The catalystcan be regenerated in the presence of H2O and H2(g).

FUEL CELLSRuthenium-Selenium Alloy Cathode CatalystSAMSUNG SDI CO LTD European Appl. 1,786,053

A cathode catalyst for a fuel cell includes a Ru-Sealloy with average particle size ≤ 6 nm, preferably3–5 nm, preferably as an amorphous catalyst. Thecomposition contains 3–20 wt.% Se vs. Ru, and Rumakes up 10–90 wt.% of the total catalyst composi-tion. The catalyst is prepared by drying a solutioncontaining RuCl3 hydrate, Ru acetylacetonate, Ru car-bonyl or a mixture, heat treating the product, thenadding a solution containing selenous acid and heattreating a second time.

Platinum-Gold Alloy CatalystJOHNSON MATTHEY PLC European Appl. 1,807,200

A catalyst for a fuel cell is formed from an alloy ofcomposition PtAuX, where X is a transition metalsuch as Cr, Ti or Cu, with (in %): 40–97 Pt, 1–40 Auand 2–20 X. The alloy may be dispersed on a con-ductive C material to form a catalyst, an electrodemay be formed from the catalyst deposited on anelectrically conductive substrate, or a catalysedmembrane formed from the catalyst deposited on apolymer electrolyte membrane.


Catalyst Layer for PEMFCCANON KK U.S. Appl. 2007/0,099,066

An electrode catalyst layer for a PEMFC has anentangled (‘cobweb-like’) structure formed by reduc-ing a thin film layer containing Pt or a Pt alloy and Oplus N and/or B. The entangled structure has thick-ness 3–100 nm and porosity 30–95%, and may becarried on a support such as C, Pt/C, Pt alloy/C, Ptblack, Pt particles, Pt alloy particles or Au particles.

Manufacture of Platinum Nanoparticles Using PlasmaAJOU UNIV. IND. COOP. FOUND. Korean Appl. 2007-0,010,715

Pt nanoparticles for an electrode catalyst in a fuelcell are synthesised using plasma technology. A Ptcompound is dissolved in water with an acid and abase in a plasma reactor. H2(g) and an inert gas aremixed and injected into the reactor. Direct or alter-nating current or microwave energy are applied viatwo electrodes, placed at the solution side and the gasside respectively, causing plasma discharge at theinterface between the Pt-containing solution and themixed gas to induce reduction to Pt nanoparticles.

CORROSION PROTECTIONCorrosion-Resistant Plating StructureGNC CO LTD Korean Appl. 2007-0,021,601

A plastic material such as a resin or an engineeringplastic is plated with a chemical plating layer of Ni orCu to provide conductivity, a layer of Cu, a layer ofAg and layers of Pt, Pd, Rh or Ru to provide corro-sion resistance. Formation of pin holes during theplating process is reduced, and galvanic corrosion issuppressed in a salt water environment.

CHEMICAL TECHNOLOGYLeaching Process for the Recovery of MetalsANGLO OPERATIONS LTD World Appl. 2007/074,360

A metal such as a Pt group metal, Au, Zn, Cu, Ti,Al, Cr, Ni, Co, Mn, Fe, Pb, Na, K or Ca can beleached from an ore in the presence of HCl to forma soluble metal chloride salt. H2SO4 and/or SO2 areadded to the leach solution during or after the leach-ing step, and a solid metal-sulfate or -sulfite salt isrecovered. HCl is regenerated and continuouslytransferred to the vapour phase, and is then capturedand returned to the leaching step.

ELECTRICAL AND ELECTRONICENGINEERINGPlating Printed Circuit BoardYMT CO LTD U.S. Appl. 2007/0,104,929

A PCB is plated as follows. A bare soldering and awire bonding portion made from Cu or Cu alloy arecoated with a Pd or Pd alloy layer, then a Au or Aualloy layer, by electroless deposition. The Pd alloy layermay contain 91–99.9 wt.% Pd and the balance P or B,and has thickness 0.05–2 μm. The Au alloy layer maycontain 99–99.99 wt.% Au with Tl, Se or a mixture,and have thickness 0.01–0.25 μm. The method may beused to coat rigid, flexible or rigid-flexible PCBs.

Enhanced Nucleation of Ru FilmsNOVELLUS SYSTEMS INC U.S. Patent 7,211,509

A Ru layer can be deposited on a dielectric substrateby exposing the substrate to an amine-containingcompound then to a Ru precursor (such asruthenocene, Ru(acac)3, Ru(CO)5, etc.), and anoptional oxidising or reducing coreactant. The amine-containing compound facilitates nucleation on thedielectric surface.

Magnetic Recording MediumFUJIFILM HOLDINGS CORP Japanese Appl. 2007-018,625

A magnetic recording medium has a B2 metal alloyseed layer, an underlayer of Ru and a magnetic layer ofCoPt coated on the surface of a non-magnetic sup-porting body. The seed layer has a column structurewith diameter 5–20 nm and its surface is oxidised. TheB2 metal alloy may consist of M:Al in the ratio 50:50,where M = Ru, Pd, Pt, Rh, Ir, Os, Ni, Fe or Mn.

Diphasic Magnetic NanomaterialHEBEI UNIV. TECHNOL. Chinese Appl. 1,943,923

A magnetic nanomaterial Sm2Fe17N3-Fe3Pt, withcrystal diameter ≤ 30 nm, includes a matrix phase ofretentive 2:17 type rare earth Fe nitride with finelydispersed nanoparticles of body-centred non-reten-tive Fe3Pt. The method of preparation includes thesteps of smelting 2–3 times at 50–300 A for 2–3 min;melting by high-frequency inductance coil in a quartztube; pre-annealing at 350ºC and 5 × 10–3 Pa for 30min; crystallising at 5 × 10–4 Pa and 700–800ºC for 25min; and cracking and nitriding at 480ºC and 1 atmfor 6 h. The material is claimed to give higher mag-netic performance than monophasic retentivemagnetic materials.

MEDICAL USESCombination Therapy Using SatraplatinGPC BIOTECH AG World Appl. 2007/054,573

A combination therapy for prevention or treatmentof cancer or tumours uses a packaged pharmaceuticalincluding a Pt-based chemotherapeutic agent such assatraplatin, plus an inhibitor of a EGFR familyreceptor or a chemotherapeutically active pyrimidineanalogue. The two components are administeredwithin about 14 days of each other.

Implantable Palladium Alloy Medical DeviceCOOK INC World Appl. 2007/070,544

An implantable medical device includes at least oneportion made of a radiopaque Pd alloy, preferablycontaining ≤ 20 wt.% Re or alternatively (in wt.%):≤ 10 Ru; ≤ 30 Rh; ≤ 30 Ir; 10–20 Pt; ≤ 30 Mo; ≤ 30 W;≤ 20 Ta; 10–50 Ag; 10–50 Ag plus 5–10 Cu; ~ 26 Agplus ~ 2 Ni; ≤ 20 Re plus ≤ 30 W; or 9.5 Pt, 9 Au,14 Cu plus 32.5 Ag. The radiopacity is at least equiv-alent to that of Pt-8 wt.% W, ultimate tensile strengthis > 200 ksi and elongation to fracture is ≤ 5%. Thedevice may be a wire guide, embolisation coil, mark-er band, stent, filter, RF ablation coil or an electrode.


NAME INDEX TO VOLUME 51Page Page Page Page

AbdelDayem, H. M. 138Abdelsalam, M. E. 208Acres, G. J. K. 34Aelterman, W. 158Ager, D. J. 172, 174Akatsuka, T. 95Akita, S. 156Aksoylu, A. 27Algieri, C. 47Al-Hashimi, M. 209Allègre, G. 96Andrés, R. 210Antolini, E. 211Arblaster, J. W. 130Archer, I. 83Arendse, M. 36Arnal, P. 185Arnold, L. 147Arnold, P. 176Aryasomayajula, L. 96Ashley, M. 116, 164Astruc, D. 71Atanasoski, R. T. 158Auberson, A. 202Aubert, C. 77Azam, L. 97

Baiker, A. 95Bakhru, H. 209Balcar, H. 71Ball, S. 204Balme, G. 76Banerjee, I. A. 49Bannat, I. 46Bañuelos Romero, F. 48Baranoff, E. 208Barbieri, G. 47Barnett, N. W. 96Bartlett, P. N. 208Bartley, J. K. 44Basset, J.-M. 185Basso, A. 21Battaini, P. 19, 200Batten, S. R. 208Baumberg, J. J. 208Bazula, P. 185Bedford, R. B. 187Behzadi, B. 95Bell, E. 22Bellemin-Laponnaz,

S. 176Beller, M. 185Bello, I. 49

Benabdellah, M. 95Bencze, L. 69, 74Benitez, M. 209Bergens, S. H. 49Berk, B. 22Bernardo, P. 47Bespalova, N. 70, 73Bhargava, R. 147Bjorklund, R. 209Blacklock, T. J. 210Bo, Z. 46Bogdanov, D. 156Bolink, H. J. 208Bonakdarpour, A. 158Bond, G. C. 48, 63Bondarev, O. G. 48Boonyanuwat, A. 185Borissova, A. 95Borodzinski, A. 48Botha, J. 145Botte, G. 28Bourikas, K. 43Bouteiller, B. 147Bouyssi, D. 76Boz, E. 74Brecq, G. 147Breit, B. 173Brintzinger, H.-H. 188Bruneau, C. 73, 77Buc, D. 49Buratto, S. K. 158Busana, M. G. 49Busqué, F. 209Bussian, D. A. 158Bykov, V. 74

Cagnola, E. A. 48Calderazzo, F. 187Cambier, F. 44Cameron, D. S. 27Campo, J. A. 46Cano, M. 46Cao, F. 46Caps, V. 43Carmona, D. 187Carroll, L. J. 156Casas, E. 209Castarlenas, R. 73Catellani, M. 187Chan, K. S. 95Chandler, K. 204Chang, H. M. 96Chang, W. H. 49

Chao, T. W. 96Chaudhari, M. K. 148Chauvin, Y. 36, 69Chen, H. 210Chen, P. 97Chen, S. 211Chen, T.-M. 47Chen, W. 97Chen, X. 95Cheng, C.-L. 98Cheng, W. 148Chengfu, X. 46Cheon, J. 98Chi, Y. 96Chifotides, H. T. 211Chiusoli, G. P. 187Choi, J. 98Chou, P.-T. 96Chu, X. 209Chuepeng, S. 148Chung, K.-I. 156Citelli, D. 32Cizmeci, M. 97Clarke, M. L. 210Clerici, M. G. 187Colley, S. 84Comin, E. 210Comotti, M. 185Copping, B. 2Coq, B. 157Cornish, L. A. 104, 189Coronado, E. 208Corro, G. 48Corti, C. W.

19, 22, 199, 202Crabtree, R. H. 176Cukic, T. 42

Dafali, A. 95Dahn, J. R. 158Danopoulos, A. 176Daran, J.-C. 97de Jésus, E. 210de March, P. 209de Meijere, A. 76de Silva, A. P. 36de Souza, R. F. 210de Vries, J. G. 16Debe, M. K. 158Deffernez, A. 43Delagrange, S. 157Delaude, L. 71Denbratt, I. 145

Deng, J. 98Denmark, S. E. 210Dent, A. J. 210Dérien, S. 77Derogatis, L. 32Deubel, D. V. 211Di Noto, V. 211Díaz-Chao, P. 156Diéguez, M. 158Díez-González, S. 177Ding, Y. 97Diver, S. 176Dixneuf, P. 70, 77Dong, Q. 208Dong, X. 49, 211Douthwaite, R. 177Dragutan, I. 69Dragutan, V. 69, 177Drioli, E. 47Drozdzak, R. 71Duan, D. 209Duhayon, C. 97Dunstan, D. E. 96Durand, R. 157Dus, R. 95Dwyer, C. L. 188

Edlund, D. J. 137Edwards, P. 84El Kadiri, S. 95Ellis, S. 204Elsevier, C. J. 16Emge, T. J. 46Endoh, E. 29Erdler, G. 29Eriksson, M. 204Ernst, K.-H. 95Esteruelas, M. 177Evans, J. 210Evans, N. 208Evenson, C. R. 136

Faccenda, V. 22Fähler, S. 95Fakir, R. 32Feast, J. 150Feaviour, M. R. 42Federsel, H.-J. 173Feindel, K. W. 49Feldhoff, A. 46Feng, K. 47Feng, Q. 156


Fensterbank, L. 77Ferrer, I. J. 156Ferri, D. 95Fiddy, S. G. 210Fierro, J. L. G. 48Fink, G. 188Finkelshtein, E. 73, 74Finsterwalder, F. 28Fischer-Bühner, J. 202Fisher, T. S. 98Flores, J. C. 210Fogg, D. 70, 73Font, J. 209Force, C. 158Fornasiero, P. 32Fraile, J. M. 187France, M. B. 210Francioso, L. 209Francis, P. S. 96Franklin, A. D. 98French, S. A. 54Froom, S. 84Frye, T. 20Fu, G. 172Fu, H. 210Fuentes, J. A. 210Fujii, H. 157Fukuda, T. 46

Gade, L. 176Galenda, A. 32Gandon, V. 77Gang, C. 46Garcia Santamaria,

S. 208García, H. 209Gautron, S. 97Gayatri 97Gebert, A. 158Ghiotti, G. 157Ghosh, R. 46Ghosh, S. 208Gielens, F. C. 96Giordano, R. 97Givord, D. 95Glisenti, A. 32Gliubizzi, R. 211Goddard, R. 48Goldman, A. S. 46Golunski, S. E. 162Gopalan, R. 158Gorman, B. A. 96Goto, S. 149Gottesfeld, S. 27Graetzel, M. 208

Graham, M. J. 208Graham, S. 157Gray, P. 31Grela, K. 71Grice, S. 22, 201Griffin, G. L. 96Griffith, W. P. 150Grigg, R. 76Gringolts, M. 73, 74Grohovskaya, L. G. 178Gross, S. 211Grubbs, R. H. 36, 69Grzeszczak, P. 95Guha, A. 158Guil, J. M. 158Guillet, B. 96

Hager, E. 128Hall, G. S. 46Hamilton, H. 136Hammouti, B. 95Hara, H. 49Harada, C. 47Harold, M. P. 157Hasegawa, T. 95Hauert, R. 95Hawkins, R. 209Hayase, S. 47Haynes, A. 187Heibel, A. 147Helmersson, U. 49Heras, J. V. 46Herrmann, H.-O. 146Hildbrandt, D. 32Hill, A. 127, 199Hirao, T. 157Hisatsune, K. 211Holderich, W. 84Holmgreen, E. M. 157Hong, H.-W. 47Hong, S. 98Hor, T. S. A. 128Hormadaly, J. 49Hou, Z. 97Howard, P. 187Hsieh, A. H. 96Huang, J. 46Huang, Y. S. 96, 98Hudson, S. 29Hultquist, G. 208Hwang, S. 49

Ichinose, I. 46Ikariya, T. 172

Ilkenhans, T. 185Imamoglu, Y. 69Imamoto, T. 172Incera Garrido, G. 185Ishibai, Y. 156Itagaki, M. 174

James, B. R. 208James, S. L. 156Janes, D. B. 98Jennings, M. C. 156Jentys, A. 185Jeon, G.-H. 211Jeon, M. K. 204Ji, S. 32Jian, S.-H. 98Jiang, D. 97Jiang, H. 209Jiang, R. 211Jiang, W. 210Jiang, X. 210Jin, C. 156, 157Jin, J. 46Johnson, B. F. G. 127Johnson, D. 83Jossifov, C. 73Jun, M.-S. 98Jun, Y. 98Juneja, J. S. 209Jung, C. H. 93Jung, W. 95Jyoti, B. 210

Kachi-Terajima, C. 95Kado, T. 47Kadyrov, R. 174Kagan, H. 172Kakeshita, T. 46Kalck, P. 97Kalyanasundaram,

K. 208Kandil, S. S. 208Kaneko, M. 47Kanzelberger, M. 46Kappenberger, P. 95Karhu, H. 209Katakura, N. 47Katib, S. M. A. 208Kayahan, M. 97Keep, A. K. 16, 204Keurentjes, J. T. F. 96Khosravi, E. 69, 73Kim, C.-S. 32Kim, H. S. 156

Kim, H.-I. 211Kim, J. 48Kim, W.-S. 156Kim, Y. 156Kiserow, D. J. 48Klein, C. 208Klingvall, R. 204Klotz, F. 200Kochubey, D. I. 209Kohbara, M. 95Kolb, G. 28Kono, M. 47Kordas, K. 209Kozak, M. 149Krantz-Rülcker, T. 209Kraushaar-Czarnetzki,

B. 185Kubokawa, M. 98Kulinska, A. 208Kündig, A. A. 158Kurashima, K. 46Kureti, S. 185Kuroda, S. 96Kwak, J. 49Kwon, Y. H. 211

Lamaty, F. 177Lamprecht, D. 148Lang, C. 23, 78Lang, K. 148L’Argentière, P. C. 48Larsson, M. 145Lassauque, N. 97Laurenczy, G. 97Lazuen Garay, A. 156Le Berre, C. 97Lebargy, S. 96Lebedeva, V. I. 209Ledoux, N. 71Lee, C. 30Lee, G. 49Lee, J. K. 156Lee, K. 49, 98Lee, W.-Y. 32Lee, Y. H. 49Lei, M. 46Lercher, J. A. 185Li, H. 148Li, J. 97Li, J.-H. 48Li, L. 98Li, W.-C. 97Li, X. 210Li, Y. 48Lian, C. 98

Page Page Page Page


Liao, J. 98Liew, K. Y. 97Lim, N.-Y. 32Lim, S. 98Lim, T.-W. 32Lin, I. 176Lin, Q. 210Lin, W. 211Lindsey, K. 22, 199Linkov, V. 32Liprandi, D. A. 48Liu, C. 49Liu, C. J. 96Liu, H. 210Liu, J. H. 204Liu, Q. 48Lo, S. H. Y. 157Loginov, Yu. N. 178Lohwongwatana, B. 201Lorenzini, F. 208Lorret, O. 157Lu, A.-H. 97Lu, T. 49Lu, T.-M. 209Lu, W. 158Luciano, R. H. 211Lundström, I. 204Lunsford, J. H. 48Luo, H. 97Luo, Y.-H. 46Lysenko, Z. 98

Maccato, C. 211Maerz, J. 200Maggiore, A. 32Mahajan, S. 208Mahmood, A. 204Maier, W. F. 93, 204Maitlis, P. M. 187Mäki-Arvela, P. 44Malacria, M. 77Mallick, K. 3Manchanda, D. 202Mann, M. 199Mao, L. 157Mao, Z. 98Mar, R. E. 158Marks, T. J. 36Marques, H. M. 36Marty, A. 95Maruyama, K. 97Maschmann, M. R. 98Mata, Y. 158Matyjaszewski, K. 74Maughon, B. R. 98

McCloskey, J. 21McKeer, I. 202Méchin, L. 96Menegazzo, N. 156Mertens, N. 158Metiu, H. 158Mikkola, J.-P. 209Miller, D. 23Mills, A. 52Milton, E. J. 210Minteer, S. 34Mirkin, M. V. 47Mishima, Y. 97Mitchell, C. 83Mitsuka, M. 46Miyagishi, S. 156Miyamae, N. 98Mizaikoff, B. 156Mochida, I. 98Mokhtar-Zadeh, T. 98Monteiro, N. 76Montini, T. 32Morandi, S. 157Moreno, A. 32Morris, G. 187Moser, M. 22Moss, J. R. 127, 128Motonaka, J. 97Mshumi, C. 78Mukherjee, P. S. 208Müllen, K. 85Müller, T. J. J. 76, 77Mundschau, M. V. 136Murakami, H. 96Muraza, O. 44Murotani, H. 97Murrer, B. 150Musa, O. 74Musavi, A. 97

Nair, B. K. R. 157Nandy, T. K. 46Narayan, R. J. 156, 157Natile, M. M. 32Navarro, M. 211Nazeeruddin,

Md. K. 208Negishi, E. 76Negro, E. 211Nekrasov, I. A. 156Nemoto, J. 47Newman, D. M. 93Newton, M. A. 210Ni, C. 158Nicoletti, S. 96

Niemeyer, J. 32Nishikawa, T. 156Nishiyama, H. 173Noda, Y. 95Nolan, S. P. 70, 177Nooten-Boom, A. 21Nordlander, E. 128Nowakowski, R. 95

O’Brien, P. 47O’Dea, J. R. 158Ogomi, Y. 47Oguma, M. 149Ohba, T. 46Okamoto, Y. 95Ormerod, D. 158Oro, L. A. 187Otsuki, J. 95Ozkan, U. S. 157

Pace, G. 211Paciello, R. 173Paglieri, S. N. 136Pàmies, O. 158Panfilov, P. 208Papadimitrakopoulos,

F. 46Park, G.-G. 32Park, I.-S. 156Park, J. 174Park, J. T. 49Park, J.-S. 32Park-Ross, P. 23Pascual, A. 156Patcas, F. C. 185Patil, N. T. 76Patrick, B. O. 208Patrick, G. 32Paul, M. 185Pearson, S. 176Pekerar, S. 211Peng, M.-L. 47Peng, X. 46Pérez, H. A. 211Pérez-Balado, C. 158Pérez-Castells, J. 77Peris, E. 177Petrova, I. V. 209Philipps, S. 32Pichon, A. 156Pietraszuk, C. 73Pimanpang, S. 209Pinilla, E. 46Plyasova, L. M. 209

Poinsignon, C. 95Poletto, F. 32Pollock, T. M. 46, 156Potyrailo, R. A. 93, 204Prada Silvy, R. 42Prasad, K. 210Prinetto, F. 157Prins, S. N. 104Prudenziati, M. 49Pruschke, T. 156Puddephatt, R. J. 156Pugh, D. 176

Qi, A. 158Qu, J. 210Quiroga, M. E. 48

Raykhtsaum, G. 202Reeve, R. 30Regalbuto, J. R. 43Regan, M. R. 49Ren, L. 46Repic, O. 210Ricci, M. 187Richardson, J. T. 43Ring, Z. 209Robbes, D. 96Roberts, G. W. 48Robinson, D. J. 36, 127Robinson, I. M. 36Robinson, T. V. 49Roff, G. J. 210Rojas, G. 74Román, E. 158Roth, S. 158Rouleau, J. M. 158Rudina, N. A. 209Rüscher, C. H. 46Russell, A. E. 30, 208

Sadler, P. J. 36Sahgal, S. 97Saitou, M. 47Sakaguchi, S. 47Sakurai, H. 157Sammells, A. F. 136Sammes, N. 49Sánchez, C. 156Sands, T. D. 98Sano, A. 97Sanz, J. 158Sato, J. 156Sauvage, X. 71

Page Page Page Page


Schaberg, P. 146Scherf, U. 85Schiraldi, D. A. 158Schmid, U. 46Schmoeckel, A. K. 158Schofield, E. R. 42Schott, F. J. P. 185Schrock, R. R. 36, 69Schultz, L. 158Schulz, G. A. S. 210Schumacher, J. O. 32Schuster, H. 22Schüth, F. 97, 185Schütze, F.-W. 147Schuurman, Y. 157Schuyten, S. 204Sclafani, J. 210Scott, A. 98Screen, T. 87Scurrell, M. S. 3, 32Seidel, H. 46Seol, H.-J. 211Serp, P. 97Sessolo, M. 208Shan, C.-C. 98Shen, G. 209Shim, J. H. 49Shimizu, H. 173Shiraishi, T. 211Sibilia, G. 32Siciliano, P. 209Silva, C. 154Singh, S. B. 97Sivaramakrishna, A. 128Smirnova, A. 49Smith, R. C. 210Soled, S. L. 43Soloveichik, G. 204Sommer, W. 177Song, H. 49Souche, Y. 95Spassov, T. 95Sprinceana, I. 32Sproule, G. I. 208Srivastava, M. 97Stevens, D. A. 158Steyn, J. 32Stobbe, D. 46Strauss, J. 22Strukul, G. 187Stuchlikova, L. 49Studenok, G. I. 178Suh, D. J. 204Sullivan, A. C. 209Sulman, E. 43Sumodjo, P. T. A. 157

Sun, E. J. 93Sun, P. 47Sun, Y. 175Sung, Y.-E. 156Sunley, G. 187Süss, R. 104, 189Svedberg, E. B. 93Swan, N. 102Sykes, R. 150

Takamizawa, S. 95Takata, F. M. 157Takei, Y. 47Takuma, Y. 211Tanaka, M. 46Tanaka, Y. 211Tandon, P. K. 97Tani, K. 157Tani, Y. 97Taylor, A. D. 31Taylor, D. K. 49Tekin, A. 97Ten Eyck, G. A. 209Tereshchenko, G. F. 209Teruel, L. 209Thiébaut, D. 97Tichit, D. 157Tiekink, E. R. T. 49Todorova, S. 95Tokimoto, T. 95Tong, H. D. 96Torralba, M. C. 46Torres, M. R. 46Touzani, R. 95Treacher, K. 84Tryon, B. 156Trzeciak, A. M. 128Tsai, D.-S. 96, 98Tsuji, M. 98Tsuji, T. 98Tsujimoto, M. 97Tsujimura, T. 145Tu, B. 47Tudor, R. 116, 164Tudose, A. 71Tulchinsky, M. L. 98Tung, C.-H. 47Türk, M. 185Turner, D. R. 208Turner, J. 149Twigg, M. V. 43Tymonko, S. A. 210

Upper, G. 185

Vaivars, G. 32van der Lingen, E. 32van der Vaart, R. 209van Eldik, R. 36van Erkel, J. 209Varadan, V. K. 96Vasam, C. 176Veith, G. M. 44Verpoort, F. 71Virtanen, P. 209Volkov, V. V. 209von Zezschwitz, P. 76Vorstman, M. A. G. 96Vovard, C. 71Vuso, K. 23

Wagener, K. B. 69, 74Wan, C.-C. 157Wan, N. 98Wang, C. 98Wang, F. 98Wang, G. 76Wang, G.-C. 209Wang, H. 97Wang, L. 96Wang, S. 96, 158Wang, T. 97Wang, Y. 48, 210Wang, Y.-Y. 157Wang, Z. 32Wark, M. 46Wasylishen, R. E. 49Waters, J. 47Watson, A. 104, 189Wears, M. L. 93Weck, M. 177Weisheit, M. 95Weisner, K. 22Welker, C. 129Whisenhunt, D. W. 204Wiesner, K. 202Willemsens, A. 158Williams, B.-J. 20Williams, J. A. G. 85Wilson, J. R. H. 209Winzer, K. 156Witcomb, M. 3Wodniecki, P. 208Wolf, E. E. 204Woo, S. I. 93, 204Wright, J. 21Wu, D. 158Wu, J. 98Wu, L.-Z. 47Wu, P. 48

Wu, Y. N. 96

Xie, J. 96Xie, X. 136Xie, Y.-X. 48Xing, W. 49Xu, B. 97Xu, Y. 48Xue, X. 49

Yabutani, T. 97Yaghi, O. 36Yamaguchi, A. 96Yamaguchi, S. 31Yamaguchi, Y. 47Yamamoto, Y. 76Yan, L. 97Yang, H. 209Yang, K. 48Yano, R. 98Yano, T. 95Yarkandi, N. H. M. 208Yasuzawa, M. 97Yates, M. 42Ye, F. 211Yermakov, A. V. 178Yi, S.-J. 211Yoon, S.-H. 98Yoon, Y.-G. 32York, A. P. E. 145, 147Youngs, W. 177Yu, J. 68Yu, R. 209Yung, M. M. 157

Zanotti-Gerosa, A. 173Zawodzinski, T. A. 158Zhang, F. 156Zhang, H. 98Zhang, J. 98Zhang, L. 95, 98Zhang, L.-P. 47Zhang, R.-Y. 47Zhang, Y. 48, 98Zhao, D. 47Zheng, X. 97Zhengfei, G. 46Zhou, H. 157Zhou, Y. 48Zhu, G. 76Zhu, H. 97Zhu, J. 98Zhu, Q.-M. 48Ziegler, C. 32

Page Page Page Page


SUBJECT INDEX TO VOLUME 51Page Page

a = abstractAcetic Acid, synthesis 97, 187Acetylenes, Sonogashira coupling 87ADMET, Grubbs catalyst 69Alcohols, C12 to C15 alcohols, production 164

2-ethylhexanol, production 116, 164EtOH, reforming 34fuel 34, 145MeOH, carbonylation, a 97

sensor 31-octanol, production 164oxidation 49, 97, 98, 204, 211

electro-, a 49, 211selective, a 97

2-propylheptanol, production 164Aldehydes, by hydroformylation 116, 164

cyclisation 16α,β-unsaturated, hydrogenation, a 209

Alkanes, dehydrogenation 63, 136isomerisation 63

Alkenes, in reactions 16, 63, 69, 76, 97Alkylation 76, 176Alkynes, reduction 16Amines, pure enantiomers, synthesis 83Amino Acids, pure enantiomers, synthesis 83Ammonia, + CH4, HCN synthesis, a 157

decomposition, a 47sensors 204

Annealing, Pt 178Anthracene, oxidation, a 97Antimalarial Agents, Ir chloroquines, a 211Arenes, reduction 16Aryl Halides, in reactions 83, 87, 127, 172, 210Arylboronic Acids, in coupling reactions 83, 87, 210Autocatalysts 34, 87, 154, 162

Benzaldehydes, oxidation, a 97Benzene, reduction 16Biaryls, preparation, a 210Boiling Points, Ir, Os, Pd, Pt, Rh, Ru 130Book Reviews, “Alcoholic Fuels” 34

“Combinatorial and High-Throughput Discoveryand Optimization of Catalysts and Materials” 93, 204

“Handbook of Homogeneous Hydrogenation” 16“Metal-catalysis in Industrial Organic Processes” 187“Metal Catalyzed Cascade Reactions” 76“Nonporous Inorganic Membranes” 136“Organic Light-Emitting Devices” 85“Recent Developments in the Organometallic

Chemistry of N-Heterocyclic Carbenes” 176“The Separation and Refining Technologies of

Precious Metals” 68Buchwald-Hartwig Couplings 172Bulk Metallic Glasses, 850 Pt 199Butene, hydroformylation 164Butyraldehydes, by hydroformylation of propylene 116, 164

Cancer, anti-, pgm complexes 36, 211Carbenes 69, 76, 176Carbon Oxides, CO, adsorption, Pd-Au, Pt-Au films, a 95

electrooxidation, a 49+ H2, hydroformylation of propylene 116, 164hydrogenation, a 97oxidation 47, 162, 185

CO2, methanation 42reduction 16supercritical, solvent 185tolerance, of PEFC anodes 27

Carbonylation 83, 97, 185, 204Cascade Reactions 76, 157Casting, jewellery alloys 19, 102, 199Catalysis, asymmetric 48, 54, 98, 127, 158, 172, 176, 187

Catalysis, (cont.)biphasic, a 210book reviews 16, 76, 176, 187, 204conferences 36, 42, 69, 83, 127, 145, 172, 185heterogeneous, a 48, 97, 157–158, 209–210homogeneous, a 48–49, 97–98, 158, 210in ionic liquids 127, 209, 210

Catalysts, activity, effects of particle size variation 63dendrimers, a 210‘non-passive’ support 127phase separation 16poisons 162production, using a plasma torch 42recycling 83, 87, 162, 209, 210supported ionic liquid (SILCA) 42, 209supported metal 42three-way, see Three-Way Catalysts

Catalysts, Iridium, electrocatalysts, Pt-IrNT, Pt-IrO2NT,Pt-Ir-IrO2NT, MeOH oxidation, a 98

RuO2-IrO2/Pt, for URFCs, a 98Pt-Ir, coal electrolysis 27

petroleum reforming 63Catalysts, Iridium Complexes, CativaTM process 187

hydrogenation: enantioselective, homogeneous, transfer 16Ir-BisP*, Ir-MiniPhos*, imine reduction 172IrCl3, + H2O2, oxidation of organic compounds, a 97MeOH carbonylation, a 97

Catalysts, Osmium Complexes, conference 36H2Os3(CO)10, derivatives, asymmetric hydrogenation 127Os3(CO)12, derivatives, asymmetric hydrogenation 127Os-NHC 69, 176OsO4, dihydroxylation of 1,2-dioxines, a 49

Catalysts, Palladium, Au-Pd/C, Au, Pd deposition 42Cu-Zn-Pd, MeOH partial oxidation 204

electrocatalysts, Pd, Pd-Co, Pd-Co-Au, ORR 27Pd, (+ H2), anode, for PEFC 27Pd coatings, anodes, for SOFCs 27Pd-Co/C, ORR activity, a 98Pt-Pd, cathodes, for DEFCs, a 211

Pd-based sulfated zirconia, lean NOx reduction, a 157Pd membrane reactors, WGSR 136Pd nanoparticles, encapsulated, porous polyurea beads 83

preparation 42Pd nanoparticles/Al hydroxide 172Pd nanoparticles/ionic liquid layer/active C cloth, a 209Pd perovskites, in autocatalysts, self-regenerating 87

in organic synthesis: Sonogashira, Suzuki coupling 87Pd/α-Al2O3, /γ-Al2O3, pellets, preparation, in L-CO2, a 48Pd/Al2O3, preparation, for hydrogenations 42

reforming of glycerol 185soybean oil hydrogenation, a 97

Pd/C, imine reduction 83Pd deposition 42soybean oil hydrogenation, a 97

Pd/membrane, alkane dehydrogenation 136Pd/ordered mesoporous C, selective oxidation, a 97Pd/oxide supports, reforming of EtOH 34Pd/SiO2, direct formation of H2O2, a 48Pd/support, selective hydrogenation of ethyne, a 48Pd-Au, selective oxidation, alkenes, H2, reducing sugars 63Pd-Pt nanoparticles, preparation 42Pd-Cu/hydrotalcite, reduction of nitrate, a 210Pd-LM-SiO2, hydrogenation of nitrobenzene 3Pt-Pd, Pt-Pd/zeolite, S resistance, a 209three-way 162

Catalysts, Palladium Complexes, allylpalladium(II) 76, 210carbonylations, atom-efficient 185conference 36coupling reactions 185, 187

synthesis, boscalid, sartans 187+ ferrocene units, Suzuki couplings 127homogeneous hydrogenation 16

Catalysts, Palladium Complexes, (cont.)Pd, migration/insertion into C–H bonds 76Pd(0), cascade reactions 76Pd(0) complex/polysiloxane capsule, a 97Pd(acac)2, carbonylation of phenol 204Pd(II) acetate/phosphines, encapsulated in beads 83[PdCl(COD)] + base, methoxycarbonylation 127PdCl2, + H2O2, oxidation of organic compounds, a 97[PdCl2{P(OPh)3}2] + base, Sonogashira coupling 127Pd + dcpmp, Suzuki couplings, a 210Pd dendrimers, a 210Pd(dppb)2, carbonylation of phenol 204Pd(II) EnCatTM BINAP30, Suzuki coupling 83Pd ethylthioglycolate modified silica, a 209Pd-NHC 69, 176Pd(OAc)2, hydrogenation of NBR, a 210Pd(OAc)2 + BINAP, Buchwald-Hartwig coupling 172Pd(OAc)2/DABCO, Suzuki-Miyaura cross-crouplings, a 48Pd(PPh3)4, for 2-chloro-5-(pyridin-2-yl) pyrimidine, a 158Pd-phosphine (+ PVP), ethene carbonylation, in MeOH 83Pd+Ph3P(O), coupling of K aryldimethylsilanolates, a 210Pd + phosphite-oxazoline ligands, Heck reactions, a 158Pd-Rh, PKR substrate generation and processing 76Pd-Smopex-111, Suzuki reactions, a 210Pd/SILCA, citral hydrogenation 42Pd(o-Tol)4, conversion of an aryl bromide, to nitrile 172reduction, CO2 16

Catalysts, Platinum, base metal oxide-doped Pt/C 204electrocatalysts, Pt, for fuel cells 27, 34, 211

inks, deposition, ink jet technology 27Pt black, cathodes, for PEMFCs, a 49Pt-coated AFM tip, cathode, for PEMFC, a 158Pt coatings, anodes, for SOFCs 27Pt containing, for fuel cells 204, 211Pt/activated C, for PEMFCs, a 158Pt/C, cathodes, for DMFCs 27

inks, deposition, ink jet technology 27Pt/C-aerogel, for PEMFCs, a 49Pt/C cloth, cathodes, for PEFC 27Pt/C nanocatalysts, for fuel cells, a 49Pt/C nanofibres, for PEMFCs, a 158Pt/Nafion ‘inks’, electrodes, for PEFCs 27Pt-Au, cathodes, O reduction, in fuel cells 63Pt-Co/C, PtMo/C, electrodes 27Pt-IrNT, Pt-IrO2NT, Pt-Ir-IrO2NT, MeOH oxidation, a 98Pt1–xMx, M = Au, Co, Mo, Ru, Sn, Ta, PEMFCs, a 158Pt-Ni carbon nitride, a 211Pt-Pd, cathodes, for DEFCs, a 211PtRu, see Catalysts, RutheniumPt-Sn, binary, ternary: anodes, for DEFCs, a 211

Pd-Pt nanoparticles, preparation 42Pt, coal electrolysis 27

conversion of NOx; reduction of NOx, by H2 185decompostion, Na borohydride 27role, catalytic converters 162S resistance, a 209

Pt black, HCN, synthesis, a 157Pt nanoparticles, preparation 42Pt/γ-Al2O3, diesel soot oxidation, a 48Pt/Al2O3, H2/NOx reaction 185

reforming of glycerol 185Pt/C, electrochemical oxidation of borohydride 27

HDCl of DCE 138preparation 42, 138

Pt/Mg(Al)O, synthesis; cascade reaction, a 157Pt/SnO2 (Pt via scCO2 deposition), CO oxidation 185Pt-Au, NO reduction, by propene 63

selective oxidation: polyols, reducing sugars 63Pt-Ir, coal electrolysis 27

petroleum reforming 63Pt-Pd, S resistance, a 209Pt-Sn, alkane dehydrogenation 63Pt-Au colloids/C, preparation 63Pt-Au/HY zeolite, alkane isomerisation 63Pt-Au/SiO2, /TiO2, /TiO2–SiO2, /Y zeolite, preparation 63

Catalysts, Platinum, (cont.)Pt2Au4/SiO2, preparation 63PtCu/, PtCuCaH/, PtCuH2/, PtCuNaH/C, preparation 138PtCuCaH/, PtCuH2/, PtCuNaH/C, HDCl of DCE 138Pt-modified TiO2, photooxidation of NOx, a 156Pt-Ni/δ-Al2O3, indirect partial oxidation of LPG 27Pt-Pd/zeolite, S resistance, a 209Pt-Sn/γ-Al2O3, diesel soot oxidation, a 48PtSnNa/ZSM-5, propane dehydrogenation, a 48Ru-Pt clusters 127RuPt nanoparticles/mesoporous SiO2, preparation 42three-way 162transition metal oxide-doped Pt/C 204

Catalysts, Platinum Complexes, conference 36cyclometallated Pt(II)/SBA-15, olefin photooxidation, a 47homogeneous hydrogenation 16

Catalysts, Rhodium, octane reforming 27Rh/γ-Al2O3, oxidation by NO, reduction by H2, a 210Rh/Al2O3, reforming of glycerol 185Rh/CeO2, preparation, reduction/oxidation treatment, a 158Rh/MgO/CeO2-ZrO2, reforming of gasoline, a 158Rh/oxide supports, reforming of EtOH 34Rh-Mn-Li-Ti/SiO2, CO hydrogenation, a 97three-way 145, 162

Catalysts, Rhodium Complexes, asymmetrichydroformylation 187

asymmetric hydrogenation, synthesis: L-DOPA,(–)-menthol, (S)-metolachlor 187

bisphosphite-Rh complex, hydroformylation 164catalyst reactivation 116cationic, cyclisation of aldehydes, enones 16conference 36[Cp*RHCl2]2 + chiral diamine, H2O soluble, ATH, a 98enantioselective hydrogenation 16homogeneous hydrogenation 16hydroformylation of olefins, LP OxoSM Process 116, 164hydrogenation, diene based polymers 16modular P-chiral ligands, asymmetric hydrogenation, a 48Monsanto process, acetic acid synthesis 187NORMAXTM Catalyst, bisphosphite-Rh complex 164Pd-Rh, PKR substrate generation and processing 76reduction, arenes, CO2, heteroaromatics 16Rh(I), alkylation of π-allyl species, cascade reactions 76Rh(I)-chloride-hexylamine, semihydrogenation, a 48Rh(acac)(CO)PPh3, as precursor 116Rh-BisP*, Rh-MiniPhos, reduction reactions 172RhCl3, + H2O2, oxidation of organic compounds, a 97[Rh(COD)2]BF4 + modular P-chiral ligands, a 48Rh-MonoPhosTM, reactions 172Rh(Norphos), Rh(Phebox), Rh-QuinoxP*, Rh-Rophos,

Rh-Solphos, Rh(TMBTP), reduction reactions 172Rh-TPPTS, biphasic hydroformylation, a 210rhodacycloalkanes, chain forming reactions 127ROPAC + CO + triphenylphoshine, hydroformylation 116SELECTORSM 10, SELECTORSM 30, in LP OxoSM 164TPP-Rh complex, hydroformylation 116, 164transfer hydrogenation 16Wilkinson’s catalyst 116, 150

Catalysts, Ruthenium, electrocatalysts, PtRu 34, 98, 158binary, ternary: anodes, for DEFCs, a 211

PtRu/C, anodes, for DMFCs, PEFCs 27Pt-Ru/CNTs, Pt-Ru-Ni/CNTs, for DMFCs, a 211PtRu/C nanofibres, for DMFCs, a 98PtRu/Vulcan C, for DMFCs, a 49Pt-Ru black, anodes, for PEMFCs, a 49Ru containing, for fuel cells 204, 211RuO2-IrO2/Pt, for URFCs, a 98

Ru, decompostion, Na borohydride 27Ru nanocatalysts, reduction of benzene 16Ru nanoparticles 42, 97Ru/Al2O3, C oxidation, in SOFCs 27Ru/ceramic foam, CO2 methanation 42Ru/SiO2, preparation, TEA as an impregnation aid 42Ru-Pt clusters 127RuPt nanoparticles/mesoporous SiO2, preparation 42


Page Page

Catalysts, Ruthenium Complexes, asymmetrichydrogenation, of ketones 54

cascade reactions 76conference 36enantioselective hydrogenation 16Grubbs catalyst 69, 76, 98, 127[H4Ru4(CO)8(P-P*)2], [H4Ru4(CO)10(P-P*)],

H4Ru4(CO)12, asymmetric hydrogenation 127homogeneous hydrogenation 16Hoveyda’s catalyst 69, 76hydrogenation, ketones 16metathesis 69, 76, 176, 187Nolan’s catalyst 69Noyori’s catalyst 54P-Phos, PhanePhos, ParaPhos 54(PCy3)2Cl2Ru=CHPh, stability, a 98reduction, arenes, CO2, heteroaromatics 16Ru alkylidenes, allenylidene, indenylidene 69Ru(BINAP), reduction of an unsaturated acid 172Ru-BINAP-DPEN, ketone reduction 172RuCl2(PPh3)3, hydrogenation of NBR, a 210Ru clusters, Fischer-Tropsch reaction 127Ru3(CO)12, derivatives, asymmetric hydrogenation 127Ru-NHC 69, 76, 176Ru-TolBINAP, Ru-XylBINAP, ketone reduction 172transfer hydrogenation 16[(S)-XylBINAP-RuH2-(S,S)-DPEN], modelling 54

CativaTM Process, acetic acid synthesis 187Clusters, Os, Ru, Ru-Pt 127Coatings, Pt black, a 47

Pt-Ir modified aluminide, on Ni-base superalloy, a 96Colloids, Pt-Au 63Combinatorial Chemistry 93, 204, 211Combustion, toluene 42Composites, diamondlike C–Pt films, a 157

Pd-polyaniline, Pd-polyaniline derivatives 3Compound Energy Formalism Model 104Conferences, 4th Cape Organometallic Symposium,

South Africa, 2006 1279th Int. Symp. on the Scientific Bases for the Preparation

of Heterogeneous Catalysts, Belgium, 2006 4240th Conference ‘Deutscher Katalytiker’, 2007 185Fuel Cells Science and Technology 2006, Italy 272007 Fuels and Emissions Conference, South Africa 145ICCC37, Cape Town, South Africa, 2006 36New Frontiers in Metathesis Chemistry, Turkey, 2006 69Novel Chiral Chemistries Japan 2007 172Sante Fe Symposium, U.S.A. 19, 199Successful Scale-Up of Catalytic Processes, U.K., 2006 83

Corrosion, Pt-Ir modified aluminide coatings, a 96Corrosion Inhibitors, for steel, Ru macrocycle, a 95Coupling Reactions 185, 187, 210Cross Metathesis 69, 98Crucibles, Pt 178CVD, aerosol-assisted, Pd sulfide thin films, a 47

Pd activation layers, a 96Cyclisation, aldehydes, enones 16

Decomposition, NH3, a 47Deformation, Ir single crystals, a 208Deformation Resistance, 99.93 wt.% Pt 178Dehydrogenation, alkanes 48, 63, 136Dendrimers, Pd, a 210Density Functional Theory, modelling, Ru catalysts 54Dental, alloys, hardening, a 211Deposition, Co/Pt, CoCr/Pt thin films 93

electroless, Cu, Cu/Pd nanoparticles activator, a 157plasma, Pd, on poly(p-xylylene), a 209scCO2, Pt, on SnO2 185

1,2-Dichloroethane, hydrodechlorination 138Diesel, emission control 145, 185

soot, oxidation, a 48Dihydroxylation, 1,2-dioxines, a 49

Electrical Conductivity, nanofibrous Pt sheets, a 46

Electrical Contacts, ohmic, Pd/C SWNTs, a 98Electrical and Electronic Engineering, a 49, 98Electrical Resistivity, Ti/Pt thin films, a 46Electrochemistry, a 47, 95, 156

polyaniline-Pd composite films 3Pt black coating, a 47Pt–diamondlike C nanocomposite thin films, a 156Pt nanoelectrodes, a 47Pt nanoparticles/C powder, anode, in Li ion batteries, a156

Electrodeposition, CoPd thin films, a 157Pd nanowires, a 98Pt black coating, a 47

Electrodeposition & Surface Coatings, a 47, 96, 157, 209Electrodes, in fuel cells, see Fuel Cells

GOx/Aunano/Ptnano/CNT, glucose sensor, a 209micro-, Pt, in wine classification, a 209nano-, Pt, electron-transfer reactions, a 47Pt nanoparticles/C powder, anode, Li ion batteries, a 156

Electroless Plating, Cu, Cu/Pd nanoparticles activator, a 157Pd, membranes, a 157

Electrolytes, H2PtCl6, + Pb acetate trihydrate, a 47Emission Control, motor vehicles 34, 87, 145, 154, 185Enamines, enantiosective hydrogenation 16Enones, cyclisation 16Enynes, cycloisomerisation 69

metathesis 69, 76, 176Ethene, carbonylation 83

hydrogenation, a 48Ethyne, selective hydrogenation, ethene-rich streams, a 48

Field-Effect Devices, gas-sensitive 204Films, diamondlike C–Pt composite, a 157

Pd-Au, Pt-Au, CO adsorption, a 95polyaniline-Pd, electrochemical behaviour 3Pt, porous, a 208

‘Final Analysis’ 52, 102, 162Fischer-Tropsch Reactions, Ru clusters 127Fuel Cells, a 49, 98, 158, 211

DAFC, fuel 34DEFC, electrocatalysts, anodes, cathodes, a 211DMFC, catalysts 27, 34, 49, 98, 204, 211fuels 27, 34, 204high-throughput screening, catalysts 27, 204, 211inks, Pt, deposition, ink jet technology 27membrane electrode assemblies 27O reduction 27, 63PEFC, catalysts 27PEMFC, catalysts 27, 34, 49, 158, 204

conducting channels, nanoscale current imaging, a 158distribution of H2O, a 49surface-modified C, as Pt catalyst support, a 158

SOFC, catalysts 27URFC, electrocatalyst, a 98

Fuels, alcohols 34, 145diesel; biodiesel 145H2 27, 145, 204natural gas 145synthetic, BTL, CTL, GTL 145

Gas Recycle Principle, in LP OxoSM 116, 164Gasoline, autothermal reforming, a 158Gauzes, N-based fertiliser production 34Glucose, sensor, a 96, 97, 209Glycerol, reforming 185

Hardening, dental alloys, a 211Hardness, 99.93% Pt 178

Pt-5% Co 102Pt-5% Cu 78, 102Pt-5% Ir, Pt-5% Pd, Pt-5% Ru 102

Heck Reactions 76, 83, 97, 158, 209, 2101-Heptyne, semihydrogenation, a 48Heteroaromatics, reduction 16High-Throughput Screening Techniques 27, 93, 204, 211History, Sir Geoffery Wilkinson, commemorative plaque 150


Page Page

Hydride, reduction, Pt-Cu/C, synthesis 138Hydrocarbons, oxidation 162Hydrodechlorination, 1,2-dichloroethane 138Hydroformylation 187, 210

low-pressure Rh-based catalyst, LP OxoSM 116, 164Hydrogen, + CO, hydroformylation of propylene 116, 164

for direct formation of H2O2, a 48from reforming, glycerol 185fuel 27, 145, 204-induced stress relaxation, in thin Pd films, a 95membranes 96, 136, 157+ NOx, reduction 185production 27, 204purification, a 47selective oxidation 63sensors 204sorption, of Mg–(Ir,Rh,Pd)–Si, a 95

Hydrogen Cyanide, synthesis, a 157Hydrogen Peroxide, formation 48, 63Hydrogenation, asymmetric 48, 54, 127, 187

asymmetric transfer 98, 172CO, a 97diastereo-; enantio-; enantioselective transfer 16diene based polymers 16ethene, a 48homogeneous 16ketones 16nitrile rubber, a 210nitrobenzene 3O2, in H2O, a 209partial, citral 42selective, a 48soybean oil, a 97transfer 16α,β-unsaturated aldehydes, a 209

Hydrotalcite, Pd-Cu/hydrotalcite, reduction of nitrate, a 210

Imines, hydrogenation 16, 98reduction 83

Ink Jet Technology, deposition, Pt catalysts, for MEAs 27Inks, Pt catalysts, for MEAs 27Ionic Liquids 127, 209, 210Iridium, boiling point, melting point 130

Pt-Ir modified aluminide coatings, a 96refining 68in sensors 204single crystals, deformation, a 208Tammann temperature 162vapour pressure equation, vapour pressure value 130

Iridium Alloys, Pt-5% Ir, hardness 102Iridium Complexes, Cp*IrClL2, precursor, for Cp*IrLR2127

iridacycles, by RCM 127Ir chloroquines, antimalarial agents, a 211trans-IrCl(CO)L2, as precursor to tricarbido complexes 127fac-[Ir(ppy)3], alkyl chains, ordered arrays, graphite, a 95luminescence, a 47, 157, 208OLEDs 85, 96, 208(PCP)Ir(NBE), + N2; (PCP)IrPhH, + N2; (PCP)Ir(N2), a 46phosphorescence, a 96, 208photoconversion 36

Iridium Compounds, IrO2, in propionic acid sensor, a 96Mg–(Ir,Rh,Pd)–Si, H sorption, a 95

Isomerisation, alkanes 63cyclo-, enynes 69

Isothermal Section, calculated, Pt-Cr-Ru 189

Jewellery, Pd, Pd alloys 19, 199Pt alloys 19, 23, 78, 102, 199

Johnson Matthey, Autocatalyst Plant, South Korea 154Pd jewellery alloys 19, 199“Platinum 2006 Interim Review” 45“Platinum 2007” 155Platinum Metals Rev. Journal Archive 2

Ketones, hydrogenations 16, 54, 98, 172

Liquid Crystals, pyrazole-based allyl-Pd complexes, a 46Liquid Recycle Principle, in LP OxoSM 164Liquidus Surface, Pt-Cr-Ru 189‘LP OxoSM Process’, hydroformylation of olefins 116, 164LPG, indirect partial oxidation 27Luminescence, Ir(III) complexes, a 47, 157, 208

Ru complexes, a 96, 209

Magnetic Storage, Co/Pt, CoCr/Pt, CoCrPtTa, PtCo, PtFe 93CoPt3 nanoparticles, FePt nanoparticles, a 98

Magnetism, CoPd thin films, a 157CoPt nanoparticles, a 49CoPt3, FePt nanoparticles, a 98FePd, FePt, a 95Fe35Pt35P30, Fe50Pt50, Fe53Pt44C3, a 158[Rh2(bza)4(pyz)]n + NO, a 95

Martensitic Transformation, FePd, a 46Mechanical Properties, Pt-5% Cu 78Medical, Pd, Pt, Rh, Ru complexes 36Medical Uses, a 158, 211Melting Points, Ir, Os, Pd, Rh, Ru 130

Pt 130, 162Membranes, Pd 96, 136, 157

Pd/polypropylene fibre, hydrogenation of O2, a 209Pd-Ag, tubular; Pd-Cu, foil 136PGM (+ ceramic oxide), PGM coatings, PGM alloy 136Pt-loaded zeolite, for H2 purification, a 47Si3N4/SiO2 radiometer, Pt thin film thermometers, a 96

Metathesis 69, 76, 176, 185, 187Methanation, CO2 42Methane, + NH3, HCN synthesis, a 157Methoxycarbonylation, iodobenzene 127Methyl Methacrylate, production, scale-up 83Microwaves, -polyol method, preparation of PtRu/CNF, a 98

in Suzuki cross-couplings, a 210MOCVD, nanostructured IrO2 crystals, a 96Modelling, reactions, chiral Ru catalysts, using DFT 54Monosaccharides, oxidation 42Monsanto Process, acetic acid synthesis 187

Nanocatalysts 49, 127Nanocomposites, Pt–diamondlike C thin films, a 156Nanoelectrodes, Pt, a 47Nanofibrous Sheets, Pt, electrical conductivity, a 46Nanoparticles, CoPt, a 49

CoPt3, a 98Cu/Pd, a 157FePt, a 98Pd 3, 36, 69, 83, 172, 209Pt, a 46, 96, 156, 209Ru 36, 97

Nanostructures, IrO2 crystals, by MOCVD, a 96Nanowires, Pd, a 98Negishi Couplings, a 158Nitrate, reduction, a 210Nitrobenzene, hydrogenation 3Nitrogen, adsorption, by [Rh2(bza)4(pyz)]n, a 95Nitrogen Oxides, NO, adsorption, by [Rh2(bza)4(pyz)]n, a 95

interaction with Rh/γ-Al2O3, a 210reduction, by propene 63

NO2, adsorption, by [Rh2(bza)4(pyz)]n, a 95NOx, photooxidation, a 156

reduction 157, 162, 185traps 145

Oil, soybean, hydrogenation, a 97OLEDs 85, 96, 208Olefins 47, 48, 69, 127, 164, 185, 187, 210Osmium, boiling point, melting point 130

refining 68Tammann temperature 162vapour pressure equation, vapour pressure value 130

Osmium Complexes, in biology 36Os pyridylazolates, in OLEDs, a 96tris-bipyridine Os pyrrole complexes, glucose sensor, a 97


Page Page

Oxidation, alcohols 49, 97, 98, 204, 211anthracene, a 97benzaldehydes, a 97CO 162, 185cyclic, Ru single crystal superalloys, a 156diesel soot, a 48electro-, CO, a 49

alcohols, a 49, 211hydrocarbons 162indirect partial, LPG 27metals, Pt-catalysed, a 208partial, MeOH 204phenanthrene, a 97PtRuAl, RuAl, a 46Rh/CeO2, a 158selective, alcohols, a 97

alkenes, H2, reducing sugars 63CO, a 47monosaccharides 42

Oxygen, for direct formation of H2O2, a 48in H2O, hydrogenation, a 209reduction, a 98, 211

in fuel cells 27, 63Oxygenates, C2-, from CO hydrogenation, a 97

Palladium, activation layers, by CVD, a 96boiling point, melting point 130layer, on poly(p-xylylene), a 209membranes 96, 136, 157, 209nanoparticles 3, 36, 69, 83, 157, 172, 209nanowires, a 98Pd, Pd-Au films, CO adsorption, a 95Pd/C SWNTs, ohmic contacts, a 98Pd-polyaniline composite materials 3refining 68Rh (first film)/Pd bilayer, H2, NH3 sensing 204in sensors 204Tammann temperature 162thick films, H2 sensing 204thin films, H-induced stress relaxation, a 95

structured surfaces, SERS, a 208vapour pressure equation, vapour pressure value 130

Palladium Alloys, Au-Pd, diffusion bonding 19Au-Pd white, for findings 199casting, for jewellery 19CoPd thin films, electrodeposition, magnetism, a 157dental, hardening, a 211FePd, martensitic transformation, a 46jewellery 19, 199membranes: Pd-Ag, tubular; Pd-Cu, foil 136950 Pd, for findings, jewellery 199Pd-Cu, Pd-Ga, Pd-Ru 19Pt-5% Pd, hardness 102solders 199TiPd, + Hf, shape memory effect, a 208‘TruPd’, for jewellery 19welding, for jewellery 199

Palladium Complexes, medicine 36nanoscale bowl-shaped hexa-Pd cage, self-assembly, a 156Pd carbenes, as catalysts, a 210Pd dithiocarbamates, for CVD, a 47Pd(hfac)2, CVD precursor, a 96Pd(II) + N-ally-N'-pyrimidin-2-ylthiourea, a 208photoconversion 36pyrazole-based allyl-Pd, liquid crystal behaviour, a 46

supramolecular architecture, a 46solvent-free synthesis, a 156

Palladium Compounds, FePd thin films, magnetism, a 95Mg–(Ir,Rh,Pd)–Si, H sorption, a 95PdCl2, Pd(NO3)2, + polyaniline 3PdCl2, skin patch tests 19Pd perovskites, preparation; autocatalysts; catalysts 87Pd sulfide thin films, by aerosol-assisted CVD, a 47PdS, by direct sulfuration of Pd layers, a 156

Patents 50–51, 99–101, 159–161, 212–214

Pauson-Khand Reactions, substrates 76Perovskites, pgm, preparation; autocatalysts; catalysts 87Petroleum, reforming 63Phase Diagrams, Al-Pt, Al-Ru 104

Cr-Pt 104, 189Cr-Ru 189Fe–Pt–Nd, a 46Pt-Au 63Pt-Ru 189

Phenanthrene, oxidation, a 97Phenols, carbonylation 204Phosphoramidites, in catalysis 16Phosphorescence, Ir(btp)2(acac), Ir(ppy)3, PtOEP 85

Ir(III) complex, a 208Ir, Os, Pt, Ru 2-pyridylazolates, a 96

Photoconversion, a 47, 96, 156–157, 208–209Ir, Pd, Pt, Ru complexes 36

Photooxidation, NOx, a 156olefins, a 47

Photoproperties, Ir, Os, Pt, Ru 2-pyridylazolates, a 96Photosensitisers, black dye/, N3/TiO2, for solar cells, a 47

Ru(bpy)32+, decomposition of NH3, a 47

Photovoltaic Materials, PdS thin films, a 156Photovoltaic Properties, tris(bpy)Ru-silica, a 209Plasma, deposition, Pd, on poly(p-xylylene), a 209

torch, for catalyst production 42Plating Baths, chloride, Co2+, Pd2+, a 157Platinum, annealing 178

black 47, 52boiling point 130crucibles 178diamondlike C–Pt composite films, a 157electrodes, see Electrodesmagnetic storage 93, 98melting point 130, 162membranes 47, 136nanofibrous sheets, conductivity, a 46nanoparticles, a 46, 96, 156, 209in oxidation of metals, a 208phase diagrams 46, 63, 104, 189porous morphologies; black, platinised, sponge 5299.93 wt.% Pt, annealing; deformation resistance 178Pt, Pt-Au films, CO adsorption, a 95Pt-Al-Cr-Ru, thermodynamic database 104Pt-Al-Ru, liquidus surface projections 104Pt-Cr-Ru 104

isothermal section, calculated; liquidus surface 189Pt-Ir modified aluminide coatings, a 96recycling 162refining 68in sensors 204Tammann temperature 162thin films, see Thin Filmsvapour pressure equation, vapour pressure value 130

Platinum Alloys, Au-Pt, diffusion bonding 19casting, for jewellery 19, 102, 199dental, hardening, a 211Fe35Pt35P30, Fe50Pt50, Fe53Pt44C3, corrosion, a 158jewellery 19, 23, 78, 102, 199nanoparticles, a 49, 98Nd3Pt4 phase, a 46850 Pt, bulk metallic glass 199Pt84:Al11:Cr3:Ru2, thermodynamic database 104Pt-Au, colloids; particles, electronic structure; phases 63Pt-Co, microsegregation 19Pt-5% Co, hardness; jewellery 102Pt-5% Cu, hardness; jewellery 78, 102Pt-5% Ir, Pt-5% Pd, hardness 102Pt-Ru, microsegregation 19Pt-5% Ru, hardness; jewellery 102950 Pt-Ru, for findings; investment cast ring 199PtRuAl, oxidation, a 46solders 199superalloys, thermodynamic database 104, 189welding, Pt-5% Cu, -5% Ru, -3% V, for jewellery 23


Page Page

Platinum Complexes, cyclometallated Pt(II)/SBA-15, a 47medicine 36OLEDs 85, 96cis-(PEt3)2Pt(OTf)2 + 1,1,1-tris(4-pyridyl)COOR, a 208photoconversion 36platinacycles, by RCM 127[PtCl2(COD)], precursor, for PtL2R2, PtL'R2 127cis-[PtCl2(PPh3)2], solvent-free synthesis, a 156[PtCl6]2–, [Pt(NH3)4]2+, as catalyst precursor 42[Pt(CO3)(PPh3)2], solvent-free synthesis, a 156Pt(II) double square cage, a 208[PtI2(CO)]2, promoter, in Ir-catalysed carbonylation, a 97Pt(II) + N-ally-N' -pyrimidin-2-ylthiourea, a 208[Pt(OH)2Me2(dpa)], self-assembly, a 156[Pt2(μ-OH)2Me4(dpa)2][B(OH)(C6F5)3]2, a 156tetra-Pt square, self-assembly, a 156

Platinum Compounds, H2PtCl6, + TiO2, a 156βNdPt, NdPt2, a 46PtCl2, + solid phosphines, reaction, a 156[Pt(NH3)4](HCO3)2 fibres, as templates, a 46Pt perovskites, preparation 87

Poisoning, catalysts 162Polymerisation, by metathesis 69Polymers, diene based, hydrogenation 16

Pd-polyaniline, Pd-polyaniline derivatives 3polystyrene, selective hydrogenation, aromatic rings, a 48poly(p-xylylene), Pd layer, a 209synthesis, by ROMP 69

Propane, dehydrogenation, a 48Propionic Acid, vapour, sensor, a 96Propylene, hydroformylation 116, 164PVD, Pd, Pd-Au, Pt, Pt-Au films, a 95

Radiometer, using thin film Pt thermometers, a 96RCM, formation, iridacycles, platinacycles 127Reactors 83, 98, 136Reduction, alkenes, alkynes, arenes, benzene, CO2,

heteroaromatics 16C-C double bonds, in synthesis 172with hydride, Pt-Cu/C 138imine 83ketones 172nitrate, a 210NO, by propene 63NOx 157, 162, 185O 27, 63, 98, 211Rh/CeO2, a 158

Refining, precious metals 68Reforming 27, 34, 63, 158, 185Relativistic Effects, Pd, eka-Pt, Pt 63Resistors, thick film, RuO2, a 49Rhodium, boiling point, melting point 130

refining 68Rh (first film)/Pd bilayer, H2, NH3 sensing 204Tammann temperature 162vapour pressure equation, vapour pressure value 130

Rhodium Complexes, [Cp*RhCl2]2, to di-alkenyl-Rh 127Cp*RhLCl2 precursors, to Cp*RhL{(CH2)n} 127dirhodium tetracarboxylates, anticancer, a 211medicine 36[Rh2(bza)4(pyz)]n, gas adsorbency, a 95Rh(II) tetramesitylporphyrin, Rh(III) porphyrin alkyls, a95Rh(I) + tris(hydroxymethyl)phosphine, H2O-soluble, a 208Wilkinson’s catalyst 116, 150

Rhodium Compounds, Mg–(Ir,Rh,Pd)–Si, H sorption, a 95Ring-Closing Metathesis, in synthesis 69ROMP, in synthesis 69Rubber, nitrile, hydrogenation, a 210Ruthenium, Al-Cr-Ru, Cr-Ru 104

boiling point, melting point 130nanoparticles 36, 97phase diagrams 104, 189Pt-Al-Cr-Ru, thermodynamic database 104Pt-Al-Ru, liquidus surface projections 104Pt-Cr-Ru, isothermal section; liquidus surface 189

Ruthenium, (cont.)refining 68Tammann temperature 162vapour pressure equation, vapour pressure value 130

Ruthenium Alloys, Pd-Ru, for jewellery 19Pt84:Al11:Cr3:Ru2, thermodynamic database 104Pt-Ru, microsegregation 19Pt-5% Ru, hardness; jewellery 102950 Pt-Ru, for findings; investment cast ring 199PtRuAl, RuAl, oxidation, a 46single crystal superalloys, oxidation, a 156

Ruthenium Complexes, in biology 36as catalyst precursors 42luminescence, a 96, 209medicine 36OLEDs, a 96photoconversion 36photosensitiser, a 47Ru(bpy)3

2+ system, decomposition of NH3, a 47RuHCl(CO)L3 precursor, to tricarbido complexes 127Ru macrocycle, corrosion inhibitor, for steel, a 95solar cells, a 47

Ruthenium Compounds, Ru perovskites, preparation 87RuIn3, semiconductor, a 156RuO2 thick film resistors, a 49RuO2/4H-SiC Schottky diodes, a 49

Schottky Diodes, RuO2/4H-SiC, a 49Semiconductors, RuIn3, a 156Sensors, glucose, a 96, 97, 209

H2 204MeOH 3NH3 204propionic acid vapour, a 96

Shape Memory Effect, TiPd, + Hf impurities, a 208Single Crystals, Ir, deformation, a 208

Ru superalloys, a 156RuIn3, a 156

Solar Cells, a 47Solders, Pd, Pt 199Sonogashira Couplings 87, 127Soot, diesel, oxidation, a 48Sputtering, magnetron, for preparing Pt/C catalysts 42Sugars, reducing, selective oxidation 63Sulfur, compounds, catalyst posion 162Sulfur Oxides, SO2, adsorption, by [Rh2(bza)4(pyz)]n, a 95Superalloys, Pt-based, thermodynamic database 104, 189

single crystal, Ru, oxidation, a 156Suzuki Couplings 83, 87, 127, 209, 210Suzuki-Miyaura Couplings, a 48

Tammann Temperature, Ir, Os, Rh, Ru, Pd, Pt 162Tetralin, amino-, synthesis 172Thermodynamic Database, Pt-based superalloys 104, 189Thermometers, Pt thin films, a 96Thick Films, Pd, H2 sensing 204

RuO2 resistors, a 49Thin Films, Co/Pt, CoCr/Pt, CoCrPtTa 93

CoPd, magnetism, a 157FePd, FePt, magnetism, a 95Pd, H-induced stress relaxation, a 95

structured surfaces, SERS, a 208Pd sulfide, a 47, 156Pt, structured surfaces, SERS, a 208

as thermometers, a 96Pt–diamondlike C nanocomposite, electrochemistry, a 156Ti/Pt, electrical resistivity, a 46

Three-Way Catalysts 145, 162Toluene, combustion 42

Vapour Pressure, equations, values, pgms 130

Water, dissolved O2, hydrogenation, a 209Water Gas Shift Reaction, Pd membrane reactors 136Welding, fusion, laser, spot, Pt jewellery alloys 23


Page Page

Platinum Metals ReviewJohnson Matthey Plc, Precious Metals Marketing, Orchard Road, Royston, Hertfordshire SG8 5HE, U.K.

E-mail: [email protected]://www.platinummetalsreview.com/

Documents

Platinum Metals Review · 2016. 1. 28. · Platinum Metals Rev., 2007, 51, (4) 166 (discussed in Part I (1)), and the process enhance-ments resulting from the move from gas to liquid