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Research ArticleSonochemical Approach to Synthesis of Co-B Catalysts andHydrolysis of Alkaline NaBH4 Solutions
Bilge CoGkuner Aysel Kantuumlrk Figen and Sabriye PiGkin
Department of Chemical Engineering Yildiz Technical University 34210 Istanbul Turkey
Correspondence should be addressed to Aysel Kanturk Figen ayselkanturkgmailcom
Received 9 March 2014 Accepted 16 May 2014 Published 11 June 2014
Academic Editor Nurettin Sahiner
Copyright copy 2014 Bilge Coskuner et alThis is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
Co-B catalysts are promising candidates for hydrogen evolution via hydrolysis of alkaline sodium borohydride (NaBH4) solutions
In the present paper a sonochemical approach was investigated for synthesis of Co-B catalysts and hydrolysis of alkaline NaBH4
solutions Sonochemical application on synthesizing process improved the intrinsic and extrinsic properties of Co-B catalysts suchas crystal spectral surface area pore volume pore diameter and particle size Co-B catalysts prepared by sonochemical approachpossessed smaller particle size higher surface area and higher pore volume than the Co-B catalysts prepared by coprecipitationsynthesis The effects of sonochemical process on hydrolysis of alkaline NaBH
4solutions were investigated by Arrhenius theory It
was clearly demonstrated that the advantages of alkaline NaBH4solution sonohydrolysis provide superficial effects on hydrogen
evolution kinetic as maximum H2generation rate (HGR) and minimum activation energy (119864
119886)
1 Introduction
NaBH4as a solid state hydrogen storagematerial for on-board
hydrogen generation systems has drawn much attention dueto its superficial properties as it is non-flable nontoxic selec-tive environmentally friendly and also one of the light weightcomplex hydrides with high hydrogen capacity (11 wt) [1ndash3]
NaBH4is self-decomposable in aqueous solutions and
can be stabilized by alkalization [2 4] Hydrogen generationfrom NaBH
4is supplied for fuel cells by means of alkaline
solution hydrolysis in contact with certain catalysts Severalresearchers have been focused on homogeneous andorheterogeneous catalysts such as acidsmetal complexesmetalsalts metal alloys and supported catalysts Nonnoble metalsespecially have attracted significant attention in turns of bothreactivity and costs Among different nonnoble catalysts suchas Co Ni Cu and Fe catalysts could be used for hydrolysisreactions of alkaline NaBH
4solutions from the view point of
low cost stability crystallinity and high activity [4ndash8]Between all nonnoble metals for hydrogen evolution via
hydrolysis of alkaline NaBH4solutions researchers have
shownmuch attention toCo-B catalysts because of their priorproperties Cavaliere et al stated that Co-B catalyst a black
solid could be classified in two categories as cobalt boride(Co119909B) and cobalt-boron alloy (Co-B) Considering this
the chemical structure of cobalt borides has been reportedunclear and obtained variety of structure as CoB Co
2B
Co3B and Co
119909B [9 10] Researchers suggested that XRD and
XPS techniques can be used to characterize Co-B structureFurthermore amorphous Co-B catalyst is identified with abroad peak centered at around 45∘ diffraction angle [11]Many methods for synthesizing of Co-B catalysts includingchemical reduction [12] sol-gel [13 14] and wet impregna-tion [15] are reported in the literature
Sonochemical approach has been performed in a largenumber of organic reactions Sonowaves that is to sayultrasonic irradiation are oscillating sound pressure waveswith a frequency from about 20 to 100MHz [16]Thismethodhas beenwidely used in the preparation of chemical materialssuch as ceramics [17] alloys [18] composites [19] andpolymers [20] due to its cavitation effect on chemical processSonowaves enhance the chemical reaction and mass transfervia the physicochemical changes in processed medium [2122] In addition to this sonowaves are proven as useful tech-nique for inhibiting particle agglomeration in chemical envi-ronments [23]The activity of catalysts can improve bymeansof using of sonowaves in catalysts preparation step [24]
Hindawi Publishing CorporationJournal of ChemistryVolume 2014 Article ID 185957 9 pageshttpdxdoiorg1011552014185957
2 Journal of Chemistry
Ultrasonicator
Magnetic stirringTemperature
controller
(a)
Cooling jacket
Stand
Watercirculation
H2 gas
Thermocouple
Injector
Ultrasonicator
Catalystsolution
Magnetic stirring
Peristaltic pump
NaBH4
(b)
Figure 1 Experimental systems (a) Coprecipitation and sono-coprecipitation synthesis system of Co-B catalyst (b) Alkaline NaBH4
sonohydrolysishydrolysis system
It has been reported that uniform spherical Co-B amorphousalloys were prepared by ultrasound assisted (50W) reductionof Co(NH
3)6
2+ with BH4
minus in aqueous solution in 30minIt is also noted that extremely extensive power or very longtime is harmful for activity and selectivity due to melting[23] Vanadium phosphorous oxide catalyst is synthesizedusing ultrasound irradiation in a relatively short time and itsactivity improved for hydrocarbon oxidation is tested [22]Uniform Ni-B amorphous alloy nanoparticles are preparedby ultrasound-assisted reduction of Ni(NH
3)6
2+ with BH4
minus
in aqueous solution and the particle size is controlled byadjusting the ultrasound power The unique characters ofamorphous alloy morphologic structure and Ni active siteswith higher electron density of this catalyst are crucial forits superior catalytic properties [25] Ultrasonic hydrolysis ofammonia borane (NH
3BH3) with sol-gel synthesized Co-B
catalyst is firstly investigated and it is noted that hydrogengeneration rate has been increased by 3779under ultrasonicconditions [26]
The aim of this study was to provide a sonochemicalapproach and investigation of effects on synthesizing of Co-B catalysts and hydrolysis of alkaline NaBH
4solutions For
confirming this Co-B catalysts were synthesized by twomethods as sono-coprecipitation and coprecipitation fromcobalt(II) chloride hexahydride (CoCl
2sdot6H2O) and boron
oxide (B2O3) and hydrolysis of alkaline NaBH
4solutions
were performed under sonowaves and magnetic stirringThe intrinsic and extrinsic properties of Co-B catalystswere discussed based on Brunauer-Emmett-Teller surfaceanalysis (BET) X-ray diffraction (XRD) Fourier transforminfrared spectroscopy (FT-IR) and scanning electron spec-troscopy (SEM) characterizations The hydrolysis of alkaline012MNaBH
4solutions were investigated under different
reaction temperatures (22∘Cndash60∘C) in presence of Co-Bcatalysts under two different conditions For identifying theeffect of sonochemical approach on hydrolysis kinetics of
alkaline NaBH4solutions Arrhenius theory was used to
determine the kinetic parameters
2 Materials and Methods
B2O3(99 purity) was supplied from Eti Mine Works
General Management-Turkey CoCl2sdot6H2O with 97 purity
used as cobalt source was purchased from Merck Sodiumhydroxide (NaOH) was purchased from Labor Technic usedas stabilizer for NaBH
4solutions NaBH
4with a minimum
purity of 96 was supplied by Fluka
21 Sonochemical Approach to Coprecipitation Synthesis ofCo-B Catalyst The system for synthesizing the Co-B cat-alysts was illustrated in Figure 1(a) In synthesis of Co-Bcatalysts two different methods were used For sonochemicalapproach reactor modified with ultrasonicator was used incoprecipitation synthesis of Co-B catalyst The laboratorytype ultrasonicator that was commonly used for cleaningpurpose was selected The ultrasonic power of the bath-typeultrasonicator (Bandelin Sonorex Super RK 255H) is 280Wand frequency of irradiation is 35 kHz Self-certificationof sono-co-precipitation synthesis which was provided bycoprecipitation synthesis of Co-B catalyst via reactor modi-fied with magnetic stirring system was used
In synthesis of Co-B catalysts firstly 05M B2O3solution
was prepared and then CoCl2sdot6H2O were added 01M
NH4OH was added by drop wise method until pH level of
solution reached 6 The solution was mixed for 2 hours at85 plusmn 3
∘C in reactor to obtain bulk structure According to theprocedure ultrasonicator or magnetic stirring (500 rpm) wasapplied during the Co-B catalyst synthesis reaction
In the synthesis of Co-B catalysts cobalt precious-CoCl2
and boron source-B2O3were solved into water CoCl
2sep-
arates into its anions and cations by the effect of 01M
Journal of Chemistry 3
Table 1 Texture properties of Co-B catalysts
Code Synthesis type Specific surface area (m2g) Pore size (cm3g) Pore volume (A)CoB-1 sono-coprecipitation 336 plusmn 016 00141 16867CoB-2 Coprecipitation 198 plusmn 011 00066 13339
NH4OH addition the synthesis reaction occurred as (1) The
coprecipitation synthesis reaction of Co-B compounds aregiven as below
9Co2+ + 2B2O3
Alkali medium997888997888997888997888997888997888997888997888997888997888rarr 2Co
3B + Co
3(BO3)2 (1)
Subsequently bulk materials were dried at approximately100∘C under the vacuum condition for overnight to eliminatethe remaining water molecules Moreover forming stablestructure catalysts were calcined at 500∘C for 4 hours in airAs a last step Co-B catalysts were prepared for characteriza-tion of the intrinsic and extrinsic properties
XRD patterns of Co-B catalysts were recorded usingPhilips Panalytical XrsquoPert-Pro diffractometer with Cu K120572radiation in a range of diffraction angles from 5∘ to 80∘ withCu K120572 radiation (120582 = 015418mm) at operating parametersof 40mA and 45 kV with 002∘ step size and speed of 1∘minThe morphology and particular size of the Co-B catalystswere observed by using SEM techniques (JEOL JSM 5410LV) The catalysts were covered with Au and made readyfor analysis by fixing to the devicersquos sample holder withthe help of a carbon sticky band Surface properties of Co-B catalysts were determined via using a surface area andporosimetry analyzer (Micromeritics ASAP 2020) Spectralproperties were characterized via FT-IR (Perkin Elmer Spec-trum One) with ATR accessories in the spectral range of4000 cmminus1ndash650 cmminus1 with a spectral resolution of 4 cmminus1 inthe transmittance mode
22 Sonochemical Approach to Hydrolysis of Alkaline NaBH4
Solutions The hydrolysis reaction of NaBH4is as given
below Four mole H2is generated during efficient hydrolysis
reaction per mole NaBH4[1ndash3]
NaBH4+ 2H2O 997888rarr NaBO
2+ 4H2 (2)
Figure 1(b) shows the systems the hydrolysis reactions ofalkaline NaBH
4solutions were carried out The 15mL glass
reactor was immersed in a system and connected to thewater filled inverter burette in order to measure the evolvedhydrogen volume The measured data was used in inves-tigation of hydrolysis kinetic To compare the results ofsonochemical hydrolysis the systemmodified with magneticstirrer and the same procedure was followed for magneticstirring (500 rpm) According to the procedure ultrasonica-tor or magnetic stirring was applied during the hydrolysis ofalkaline NaBH
4solutions
In the experiments 10 wt NaOH alkaline 012MNaBH
4was hydrolyzed in presence of 05mg catalysts The
reactions applied in range of 22∘Cndash60∘C with temperaturecontrolling system
The kinetic investigation of sonochemical and magneticstirring hydrolysis of alkaline NaBH
4solution was identified
via Arrhenius theory The characterization of hydrolysisreaction behavior was enlightened by zero-order first-orderand second-order reaction kinetic models The activationenergies and rate constants were determined via Arrheniustheory [12 26 27]
In literature zero-order reaction is shown as belowmodelgenerally defined as reactant independent kinetic modelIn the model 119862NaBH
4
is the concentration 119903 is the rate ofreaction and 119896 is the reaction rate constant based on thesolution volume
119889119862NaBH4
119889119905= minus119903NaBH
4
= minus119896 (119879) (3)
Equation (3) is formed as below when the integration isapplied
(119862NaBH40
minus 119862NaBH4
) = minus119896 (119879) sdot 119905 (4)
First-order reaction model is dependent on the reactantsrsquoconcentration and its basic (5) and integration applied forms(6) are shown below
119889119862NaBH4
119889119905= minus119903NaBH
4
= minus119896 (119879) sdot 119862NaBH4
(5)
ln(119862NaBH
40
119862NaBH4
) = 119896 (119879) sdot 119905 (6)
The second-order reaction model is also dependent onreactants concentration with second degree and integratedforms are shown below
119889119862NaBH4
119889119905= minus119903NaBH
4
= minus119896 (119879) sdot 1198622
NaBH4
(7)
(1
119862NaBH4
minus1
119862NaBH40
) = minus119896 (119879) sdot 119905 (8)
3 Results and Discussion
31 Sonochemical Approach to Coprecipitation Synthesis of Co-B Catalyst Co-B catalysts were synthesized via two differentsystems (Figure 1(a)) The CoB-1 catalyst was synthesizedwith sonochemical approach and CoB-2 which used as con-trol sample was synthesized bymagnetic stirring systemThecatalysts were codded according to their synthesis methods(Table 1)
Table 1 shows the textural properties of Co-B catalystsComparing the specific surface areas of CoB-1 catalyst withCoB-2 catalyst the sonochemical approach a considerablyincreased the surface area of catalyst up to 70 With thismethod not only specific surface area increased but also other
4 Journal of Chemistry
(a)
(b)
Figure 2 The SEM images of Co-B catalysts with times1000 (left) and times5000 (right) magnification (a) CoB-1 catalyst (b) CoB-2 catalyst
Table 2 Particle size distribution of Co-B catalysts
CodeAverage particle
size(120583m)
Maximumparticle size
(120583m)
Minimumparticle size
(120583m)CoB-1 125 277 030CoB-2 300 739 057
texture properties as pore size and volume of catalysts wereimproved up to 114 and 26 respectively
Figure 2 shows the SEM images of Co-B catalysts at1000 and 5000 magnification Particles of Co-B catalystsynthesized by sonochemical approach were homogeneouslydispersed and smaller than coprecipitation synthesized Co-Bcatalyst
Table 2 shows average minimum andmaximum particlesizes were measured from SEM images It was indicated thatCo-B prepared with sonochemical coprecipitation synthesiswas shown a smaller average size of 125 120583m and particle sizeof the catalyst was reduced up to 58 (Table 2) BET resultswere consistent with the SEM results
Figure 3 shows XRD patterns of synthesized Co-B cata-lysts Comparing XRD pattern of synthesized catalysts withthe standard diffraction spectrum (JCPDS 00-012-0443 and01-073-1540) the synthesized product was crystalline Co
3B
and Co3(BO3)2 The sharpness of XRD reflections clearly
050
100150200250300350
5 17 29 41 53 65 77 89
Cou
nts
CoB-1CoB-2
JPCDS 00-012-0443JPCDS 01-073-1540
ΔΔΔ
lowast
lowastlowastlowastlowastlowast
ΔΔ
ΔΔ
Δ
Δ
ΔΔ Δ
ΔΔ
Δ ΔΔΔΔ
Δ
lowast
2120579 (∘)
CoB3
Co3(BO3)2
Figure 3 The XRD patterns of Co-B catalysts
shows that the synthesized Co-B catalysts were highly crys-talline The characteristic peaks of phases were indexed inXRD patterns It was clear that sonochemical treatment doesnot affect the crystalline phases of Co-B catalysts
Figure 4 shows FT-IR spectrums of Co-B catalysts In adirect comparison of the observed FT-IR spectrums of bothcatalysts it was clearly seen that B-O band frequencies weredetected at the same wave number regions The bands at3197 cmminus1 and 3206 cmminus1 corresponded to vibration of H-O groups The bands at 1403 cmminus1 and 1350ndash935 cmminus1 werecontributed asymmetric stretching of B-O The bands were
Journal of Chemistry 5
0
20
40
60
80
100
120
650 1150 1650 2150 2650 3150 3650Wavenumber
CoB-2CoB-1
T(
)
(cmminus1)
Figure 4 The FT-IR spectrum of Co-B catalysts
0
20
40
60
80
0 5 10 15
Gen
erat
ed H
2vo
lum
e (m
L)
Time (min)
Alkaline sonohydrolysis
40∘C
60∘C
80∘C
NaBH4
(a)
Gen
erat
ed H
2vo
lum
e (m
L)
0
20
40
60
80
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysis
22∘C
40∘C
60∘C
NaBH4
(b)
Figure 5 Hydrogen generation volume versus time for sonohydrolysis and magnetic stirring hydrolysis of alkaline (10wt) 012 NaBH4
solutions in presence of 05mg CoB-1 catalyst
assigned between 950ndash870 cmminus1 and 710ndash795 cmminus1 and weresymmetric stretching band of B-O [28ndash30]
CoB-1 catalysts prepared via sonochemical coprecipita-tion synthesis show the best intrinsic and extrinsic propertiesthat are contributing factors to the catalytic activity Itwas concluded to start sonohydrolysis of alkaline NaBH
4
solutions with CoB-1 catalysts which were prepared viasonochemical coprecipitation synthesis
32 Sonochemical Approach to Hydrolysis of Alkaline NaBH4
Solutions In order to investigate the effect of sonochemicalapproach hydrolysis of alkaline NaBH
4solutions in presence
of CoB-1 catalyst were carried out with two different pro-cedures The evaluated H
2volume versus time during the
reactions was given in Figure 5 The H2generation started
immediately after catalyst contact with alkaline NaBH4solu-
tion As a result of this CoB-1 catalyst did not have inductionperiod to be active Effect of increasing in temperature wasshown in Figure 5TheH
2evolution shows direct proportion
with temperature in both systems In sonochemical alkalineNaBH
4solution hydrolysis hydrolysis time dropped 140min
from 941min by increasing of temperature from 22∘C to60∘C The same tendency was observed in magnetic stirringhydrolysis and reaction time decreased to 1388min
Figure 6 shows the effects of temperature and sono-waves on hydrogen generation It was clearly seen that bycomparing two different approach sono-waves developed thehydrolysis characteristics of system via cavitation on surfaceof catalystThe ultrasonic approach improved the interactionbetween the Co-B catalyst and alkaline NaBH
4solution
and made homogeneous distribution in the alkaline NaBH4
6 Journal of Chemistry
0
2000
4000
6000
8000
10000
40 60 80
Alkaline hydrolysis
SonohydrolysisMagnetic stirring hydrolysis
Temperature (∘C)
H2
gene
ratio
n ra
te (H
2ca
t)minus1
minus1
mL
min
gNaBH4
Figure 6Hydrogen generation rate comparison versus temperaturefor sonohydrolysis and magnetic stirring hydrolysis of alkaline(10wt) 012 NaBH
4solutions in presence of 05mg CoB-1 catalyst
solution and CoB-1 catalyst During the sonohydrolysiscavitation bubbles created high energy effects and this causedcontinuous acceleration of hydrogen generation rate [19]As can be seen ultrasonic treatment during the hydrolysisresults in maximum increase in the hydrogen generationfrom alkaline NaBH
4solution up to 65 at 40∘CThe authors
suggest to use of sonohydrolysis instead of magnetic stirringhydrolysis for improving the hydrogen generation rate ofsystem
Figure 7 shows the kinetic investigation of sonochemi-cal and magnetic stirring hydrolysis in presence of CoB-1catalyst The characterization of hydrolysis reaction behaviorwas identified by zero-order first-order and second-orderreaction kinetic models and Arrhenius theory As seen fromFigure 7 in both hydrolysis conditions the hydrolyses ofalkaline NaBH
4solutions were in compliance with zero-
order reaction kineticmodel and this indicated that hydrogengeneration rate was independent from concentration ofNaBH
4 Depending onArrhenius theory activation energy of
sonohydrolysis of alkalineNaBH4solutionwas 4615 kJsdotmolminus1
and its Arrhenius rate constant was 1989minminus1 For hydrol-ysis of alkaline NaBH
4solution which was carried out in
magnetic stirring systems the kinetic valueswere determinedas 5168 kJsdotmolminus1 activation energy and 1516minminus1 Arrheniusrate constant
In literature Co containing catalysts activation ener-gies were determined and summarized in Table 3 Theactivation energies of Co containing catalysts show vari-ety for example Copowder (7500 kJsdotmolminus1) Co-Raneyform (5370 kJsdotmolminus1) and active carbon supported Co-B(5780 kJsdotmolminus1) were relatively higher than our results whileCo nanoparticle (3500 kJsdotmolminus1) was lowerThe hydrolysis ofalkaline NaBH
4solution was carried out with sonochemical
approach the reaction kinetic was improved and value ofthem was decreased up to 12
Table 3 Activation energies in presence of various Co-basedcatalysts
Catalyst Activation energy(kJsdotmolminus1) References
Co powder 7500 [31]
Co nanoparticle 3500 [13]
Co (120572-Al2O3 support) 3263 [32]
Co (Raney form) 5370 [33]
Co-B (active carbon support) 5780 [34]
Co-B powder 6487 [12]
Co-B (clay support) 5632 [35]
Co-B 5273 [36]
CoB-1 (sonohydrolysis) 4615 At thiswork
CoB-1 (magnetic stirringhydrolysis) 5168 At this
work
4 Conclusion
In the present study sonochemical approach to coprecipi-tation synthesis of Co-B catalyst and hydrolysis of alkalineNaBH
4solutions was introducedThe following points result
from this studyThe sono-co-precipitation of CoCl
2sdot6H2O and B
2O3in
aqueous solution at pH 6 was proven to be a promisingprocedure in order to obtain Co-B crystalline catalyst withuniform 125 120583m particle size improved surface area andtexture properties On the other hand it was found that sono-chemical approach did not affect the crystalline structure andspectral properties of Co-B catalyst yet
The improving effect of sonochemical process on hydrol-ysis of alkaline NaBH
4solutions was approved when it
was compared with magnetic stirring system kinetic resultsHydrogen generation rate of alkaline NaBH
4solutions via
sonohydrolysis method in presence of CoB-1 catalyst hasshown enhanced influence at all temperatures Activationenergy as 4615 kJsdotmolminus1 of sonochemical coprecipitationsynthesized Co-B catalyst has compatible value comparedwith literature (32ndash75 kJsdotmolminus1) Rate law was formulized asgiven below
119903NaBH4
= 1989 sdot 119890minus4615RT (9)
As a result of this study the ultrasonicwaves improved theintrinsic and extrinsic properties of Co-B catalyst propertiesas specific surface area increased up to 70 particle sizedecreased up to 58 and hydrogen generation rate increasedup to 64 As can be seen sonochemical coprecipitationand sonohydrolysis proved to be promising techniques forsynthesis of Co-B catalyst and hydrolysis
Journal of Chemistry 7
000
002
004
006
008
010
012
014
0 5 10 15 20Time (min)
Alkaline sonohydrolysis Zero-order reaction kinetic
000
100
200
300
400
500
0 5 10 15 20Time (min)
Alkaline sonohydrolysis First-order reaction kinetic
000
10000
20000
30000
40000
50000
60000
0 5 10 15 20Time (min)
Alkaline sonohydrolysis Second-order reaction kinetic
000
002
004
006
008
010
012
014
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisZero-order reaction kinetic
000
100
200
300
400
500
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisFirst-order reaction kinetic
000
10000
20000
30000
40000
50000
60000
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisSecond-order reaction kinetic
Ln(C
CN
aBH
4)C
minusC
NaB
H4
(M)
Cminus
CN
aBH
4(M
)(1
CN
aBH
4)minus
(1C
)
22∘C
40∘C
60∘C
22∘C
40∘C
60∘C
NaBH4 NaBH4
NaBH4NaBH4
NaBH4 NaBH4
Ln(C
CN
aBH
4)
(1C
NaB
H4)minus
(1C
)
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
Figure 7The kinetic investigation the zero first and second reaction kinetic models for sonohydrolysis and magnetic stirring hydrolysis ofalkaline (10wt) 012M NaBH
4solutions
Symbols Used
119903 [H2molsdotminminus1sdotgminus1 cat] H
2generation rate
119864119886 [kJsdotmolminus1] Activation energy119877 [kJsdotmolminus1 sdot∘Cminus1] Gas constant119879 [∘C] Temperature
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
The authors would like to thank the Yildiz Technical Univer-sity Research Foundation (Project no 2012-07-01-YL02) forits financial support
References[1] S C Amendola S L Sharp-Goldman M S Janjua et al ldquoSafe
portable hydrogen gas generator using aqueous borohydridesolution and Ru catalystrdquo International Journal of HydrogenEnergy vol 25 no 10 pp 969ndash975 2000
8 Journal of Chemistry
[2] R Retnamma A Q Novais and C M Rangel ldquoKinetics ofhydrolysis of sodium borohydride for hydrogen productionin fuel cell applications a reviewrdquo International Journal ofHydrogen Energy vol 36 no 16 pp 9772ndash9790 2011
[3] O Akdim U B Demirci D Muller and P Miele ldquoCobalt(II) salts performing materials for generating hydrogen fromsodiumborohydriderdquo International Journal of Hydrogen Energyvol 34 no 6 pp 2631ndash2637 2009
[4] J Liang Y Li Y Huang et al ldquoSodium borohydride hydrolysison highly efficient Co-BPd catalystsrdquo International Journal ofHydrogen Energy vol 33 no 15 pp 4048ndash4054 2008
[5] U B Demirci O Akdim J Andrieux J Hannauer RChamoun and P Miele ldquoSodium borohydride hydrolysis ashydrogen generator Issues state of the art and applicabilityupstream froma fuel cellrdquo Fuel Cells vol 10 no 3 pp 335ndash3502010
[6] US Department of Energy Hydrogen Program 2007httpwwwhydrogenenergygov
[7] U B Demirci and P Miele ldquoSodium borohydride versusammonia borane in hydrogen storage and direct fuel cellapplicationsrdquo Energy and Environmental Science vol 2 no 6pp 627ndash637 2009
[8] B H Liu and Z P Li ldquoA review Hydrogen generation fromborohydride hydrolysis reactionrdquo Journal of Power Sources vol187 no 2 pp 527ndash534 2009
[9] S Cavaliere J Hannauer U B Demirci O Akdim and PMieleldquoEx situ characterization of N
2H4- NaBH
4- and NH
3BH3-
reduced cobalt catalysts used in NaBH4hydrolysisrdquo Catalysis
Today vol 170 no 1 pp 3ndash12 2011[10] H I Schlesinger E R Brown A E Finholitam J R Gilbreathh
H R Hoekstra and E A Hyde ldquoProcedures for the preparationof methyl boraterdquo Journal of American Chemical Society vol 75no 1 pp 213ndash215 1953
[11] A M Ozerova V I Simagina O V Komova et al ldquoCobaltborate catalysts for hydrogen production via hydrolysis ofsodium borohydriderdquo Journal of Alloys and Compounds vol513 pp 266ndash272 2012
[12] S U Jeong R K Kim E A Cho et al ldquoA study on hydrogengeneration from NaBH
4solution using the high-performance
Co-B catalystrdquo Journal of Power Sources vol 144 no 1 pp 129ndash134 2005
[13] R Khan S W Kim T-J Kim and C-M Nam ldquoComparativestudy of the photocatalytic performance of boron-iron Co-doped and boron-doped TiO
2nanoparticlesrdquoMaterials Chem-
istry and Physics vol 112 no 1 pp 167ndash172 2008[14] A Kanturk Figen and B Coskuner ldquoA novel perspective for
hydrogen generation from ammonia borane (NH3BH3) with
Co-B catalysts lsquoultrasonic Hydrolysisrsquordquo International Journal ofHydrogen Energy vol 38 no 6 pp 2824ndash2835 2013
[15] C C Yang M S Chen and Y W Chen ldquoHydrogen generationby hydrolysis of sodium borohydride on CoBSiO
2catalystrdquo
International Journal ofHydrogenEnergy vol 36 no 2 pp 1418ndash1423 2011
[16] R Patil P Bhoir P Deshpande T Wattamwar M Shirude andP Chaskar ldquoRelevance of sonochemistry or ultrasound (US)as a proficient means for the synthesis of fused heterocyclesrdquoUltrasonics Sonochemistry vol 20 no 6 pp 1327ndash1336 2013
[17] T Q Liu O Sakurai N Mizutani and M Kato ldquoPreparationof spherical fine ZnO particles by the spray pyrolysis methodusing ultrasonic atomization techniquesrdquo Journal of MaterialsScience vol 21 no 10 pp 3698ndash3702 1986
[18] S L Che K Takada K Takashima O Sakurai K Shinozakiand N Mizutani ldquoPreparation of dense spherical Ni particlesand hollow NiO particles by spray pyrolysisrdquo Journal of Materi-als Science vol 34 no 6 pp 1313ndash1318 1999
[19] C L Bianchi E Gotti L Toscano and V Ragaini ldquoPreparationof PdC catalysts via ultrasound a study of the metal distribu-tionrdquo Ultrasonics Sonochemistry vol 4 no 4 pp 317ndash320 1997
[20] S S Ostapenko L Jastrzebski J Lagowski and B SoporildquoIncreasing short minority carrier diffusion lengths in solar-grade polycrystalline silicon by ultrasound treatmentrdquo AppliedPhysics Letters vol 65 no 12 pp 1555ndash1557 1994
[21] M Run SWu andGWu ldquoUltrasonic synthesis ofmesoporousmolecular sieverdquo Microporous and Mesoporous Materials vol74 no 1-3 pp 37ndash47 2004
[22] U R Pillai E Sahle-Demessie and R S Varma ldquoAlterna-tive routes for catalyst preparation use of ultrasound andmicrowave irradiation for the preparation of vanadium phos-phorus oxide catalyst and their activity for hydrocarbon oxida-tionrdquo Applied Catalysis A General vol 252 no 1 pp 1ndash8 2003
[23] H LiH Li J ZhangWDai andMQiao ldquoUltrasound-assistedpreparation of a highly active and selective Co-B amorphousalloy catalyst in uniform spherical nanoparticlesrdquo Journal ofCatalysis vol 246 no 2 pp 301ndash307 2007
[24] M G Sulman ldquoEffects of ultrasound on catalytic processesrdquoRussian Chemical Reviews vol 69 no 2 pp 165ndash177 2000
[25] H Li J Zhang and H Li ldquoUltrasound-assisted preparationof a novel Ni-B amorphous catalyst in uniform nanoparticlesfor p-chloronitrobenzene hydrogenationrdquo Catalysis Communi-cations vol 8 no 12 pp 2212ndash2216 2007
[26] A J Hung S F Tsai Y Y Hsu J R Ku Y H Chen and CC Yu ldquoKinetics of sodium borohydride hydrolysis reaction forhydrogen generationrdquo International Journal ofHydrogen Energyvol 33 no 21 pp 6205ndash6215 2008
[27] O Levenspiel Chemical Reaction Engineering John Wiley ampSons New York NY USA 3rd edition 1999
[28] L Jun X Shuping and G Shiyang ldquoFT-IR and Ramanspectroscopic study of hydrated boratesrdquo Spectrochimica ActaA Molecular Spectroscopy vol 51 no 4 pp 519ndash532 1995
[29] A Kanturk M Sari and S Piskin ldquoSynthesis crystal structureand dehydration kinetics of NaB(OH)
4sdot2H2Ordquo Korean Journal
of Chemical Engineering vol 25 no 6 pp 1331ndash1337 2008[30] Q Zhang Y Wu X Sun and J Ortega ldquoKinetics of catalytic
hydrolysis of stabilized sodium borohydride solutionsrdquo Indus-trial and Engineering Chemistry Research vol 46 no 4 pp1120ndash1124 2007
[31] J Andrieux D Swierczynski L Laversenne et al ldquoAmultifactorstudy of catalyzed hydrolysis of solidNaBH
4on cobalt nanopar-
ticles thermodynamics and kineticsrdquo International Journal ofHydrogen Energy vol 34 no 2 pp 938ndash951 2009
[32] B H Liu Z P Li and S Suda ldquoNickel- and cobalt-basedcatalysts for hydrogen generation by hydrolysis of borohydriderdquoJournal of Alloys and Compounds vol 415 no 1-2 pp 288ndash2932006
[33] W Ye H Zhang D Xu L Ma and B Yi ldquoHydrogen generationutilizing alkaline sodium borohydride solution and supportedcobalt catalystrdquo Journal of Power Sources vol 164 no 2 pp 544ndash548 2007
[34] J Zhao H Ma and J Chen ldquoImproved hydrogen generationfrom alkaline image solution using carbon-supported image ascatalystsrdquo International Journal of Hydrogen Energy vol 32 no18 pp 4711ndash4716 2007
Journal of Chemistry 9
[35] H Tian Q Guo and D Xu ldquoHydrogen generation fromcatalytic hydrolysis of alkaline sodium borohydride solutionusing attapulgite clay-supported Co-B catalystrdquo Journal ofPower Sources vol 195 no 8 pp 2136ndash2142 2010
[36] C H Liu B H Chen C L Hsueh J R Ku M S Jeng and FTsau ldquoHydrogen generation from hydrolysis of sodium boro-hydride using Ni-Ru nanocomposite as catalystsrdquo InternationalJournal of Hydrogen Energy vol 34 no 5 pp 2153ndash2163 2009
Submit your manuscripts athttpwwwhindawicom
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CatalystsJournal of
2 Journal of Chemistry
Ultrasonicator
Magnetic stirringTemperature
controller
(a)
Cooling jacket
Stand
Watercirculation
H2 gas
Thermocouple
Injector
Ultrasonicator
Catalystsolution
Magnetic stirring
Peristaltic pump
NaBH4
(b)
Figure 1 Experimental systems (a) Coprecipitation and sono-coprecipitation synthesis system of Co-B catalyst (b) Alkaline NaBH4
sonohydrolysishydrolysis system
It has been reported that uniform spherical Co-B amorphousalloys were prepared by ultrasound assisted (50W) reductionof Co(NH
3)6
2+ with BH4
minus in aqueous solution in 30minIt is also noted that extremely extensive power or very longtime is harmful for activity and selectivity due to melting[23] Vanadium phosphorous oxide catalyst is synthesizedusing ultrasound irradiation in a relatively short time and itsactivity improved for hydrocarbon oxidation is tested [22]Uniform Ni-B amorphous alloy nanoparticles are preparedby ultrasound-assisted reduction of Ni(NH
3)6
2+ with BH4
minus
in aqueous solution and the particle size is controlled byadjusting the ultrasound power The unique characters ofamorphous alloy morphologic structure and Ni active siteswith higher electron density of this catalyst are crucial forits superior catalytic properties [25] Ultrasonic hydrolysis ofammonia borane (NH
3BH3) with sol-gel synthesized Co-B
catalyst is firstly investigated and it is noted that hydrogengeneration rate has been increased by 3779under ultrasonicconditions [26]
The aim of this study was to provide a sonochemicalapproach and investigation of effects on synthesizing of Co-B catalysts and hydrolysis of alkaline NaBH
4solutions For
confirming this Co-B catalysts were synthesized by twomethods as sono-coprecipitation and coprecipitation fromcobalt(II) chloride hexahydride (CoCl
2sdot6H2O) and boron
oxide (B2O3) and hydrolysis of alkaline NaBH
4solutions
were performed under sonowaves and magnetic stirringThe intrinsic and extrinsic properties of Co-B catalystswere discussed based on Brunauer-Emmett-Teller surfaceanalysis (BET) X-ray diffraction (XRD) Fourier transforminfrared spectroscopy (FT-IR) and scanning electron spec-troscopy (SEM) characterizations The hydrolysis of alkaline012MNaBH
4solutions were investigated under different
reaction temperatures (22∘Cndash60∘C) in presence of Co-Bcatalysts under two different conditions For identifying theeffect of sonochemical approach on hydrolysis kinetics of
alkaline NaBH4solutions Arrhenius theory was used to
determine the kinetic parameters
2 Materials and Methods
B2O3(99 purity) was supplied from Eti Mine Works
General Management-Turkey CoCl2sdot6H2O with 97 purity
used as cobalt source was purchased from Merck Sodiumhydroxide (NaOH) was purchased from Labor Technic usedas stabilizer for NaBH
4solutions NaBH
4with a minimum
purity of 96 was supplied by Fluka
21 Sonochemical Approach to Coprecipitation Synthesis ofCo-B Catalyst The system for synthesizing the Co-B cat-alysts was illustrated in Figure 1(a) In synthesis of Co-Bcatalysts two different methods were used For sonochemicalapproach reactor modified with ultrasonicator was used incoprecipitation synthesis of Co-B catalyst The laboratorytype ultrasonicator that was commonly used for cleaningpurpose was selected The ultrasonic power of the bath-typeultrasonicator (Bandelin Sonorex Super RK 255H) is 280Wand frequency of irradiation is 35 kHz Self-certificationof sono-co-precipitation synthesis which was provided bycoprecipitation synthesis of Co-B catalyst via reactor modi-fied with magnetic stirring system was used
In synthesis of Co-B catalysts firstly 05M B2O3solution
was prepared and then CoCl2sdot6H2O were added 01M
NH4OH was added by drop wise method until pH level of
solution reached 6 The solution was mixed for 2 hours at85 plusmn 3
∘C in reactor to obtain bulk structure According to theprocedure ultrasonicator or magnetic stirring (500 rpm) wasapplied during the Co-B catalyst synthesis reaction
In the synthesis of Co-B catalysts cobalt precious-CoCl2
and boron source-B2O3were solved into water CoCl
2sep-
arates into its anions and cations by the effect of 01M
Journal of Chemistry 3
Table 1 Texture properties of Co-B catalysts
Code Synthesis type Specific surface area (m2g) Pore size (cm3g) Pore volume (A)CoB-1 sono-coprecipitation 336 plusmn 016 00141 16867CoB-2 Coprecipitation 198 plusmn 011 00066 13339
NH4OH addition the synthesis reaction occurred as (1) The
coprecipitation synthesis reaction of Co-B compounds aregiven as below
9Co2+ + 2B2O3
Alkali medium997888997888997888997888997888997888997888997888997888997888rarr 2Co
3B + Co
3(BO3)2 (1)
Subsequently bulk materials were dried at approximately100∘C under the vacuum condition for overnight to eliminatethe remaining water molecules Moreover forming stablestructure catalysts were calcined at 500∘C for 4 hours in airAs a last step Co-B catalysts were prepared for characteriza-tion of the intrinsic and extrinsic properties
XRD patterns of Co-B catalysts were recorded usingPhilips Panalytical XrsquoPert-Pro diffractometer with Cu K120572radiation in a range of diffraction angles from 5∘ to 80∘ withCu K120572 radiation (120582 = 015418mm) at operating parametersof 40mA and 45 kV with 002∘ step size and speed of 1∘minThe morphology and particular size of the Co-B catalystswere observed by using SEM techniques (JEOL JSM 5410LV) The catalysts were covered with Au and made readyfor analysis by fixing to the devicersquos sample holder withthe help of a carbon sticky band Surface properties of Co-B catalysts were determined via using a surface area andporosimetry analyzer (Micromeritics ASAP 2020) Spectralproperties were characterized via FT-IR (Perkin Elmer Spec-trum One) with ATR accessories in the spectral range of4000 cmminus1ndash650 cmminus1 with a spectral resolution of 4 cmminus1 inthe transmittance mode
22 Sonochemical Approach to Hydrolysis of Alkaline NaBH4
Solutions The hydrolysis reaction of NaBH4is as given
below Four mole H2is generated during efficient hydrolysis
reaction per mole NaBH4[1ndash3]
NaBH4+ 2H2O 997888rarr NaBO
2+ 4H2 (2)
Figure 1(b) shows the systems the hydrolysis reactions ofalkaline NaBH
4solutions were carried out The 15mL glass
reactor was immersed in a system and connected to thewater filled inverter burette in order to measure the evolvedhydrogen volume The measured data was used in inves-tigation of hydrolysis kinetic To compare the results ofsonochemical hydrolysis the systemmodified with magneticstirrer and the same procedure was followed for magneticstirring (500 rpm) According to the procedure ultrasonica-tor or magnetic stirring was applied during the hydrolysis ofalkaline NaBH
4solutions
In the experiments 10 wt NaOH alkaline 012MNaBH
4was hydrolyzed in presence of 05mg catalysts The
reactions applied in range of 22∘Cndash60∘C with temperaturecontrolling system
The kinetic investigation of sonochemical and magneticstirring hydrolysis of alkaline NaBH
4solution was identified
via Arrhenius theory The characterization of hydrolysisreaction behavior was enlightened by zero-order first-orderand second-order reaction kinetic models The activationenergies and rate constants were determined via Arrheniustheory [12 26 27]
In literature zero-order reaction is shown as belowmodelgenerally defined as reactant independent kinetic modelIn the model 119862NaBH
4
is the concentration 119903 is the rate ofreaction and 119896 is the reaction rate constant based on thesolution volume
119889119862NaBH4
119889119905= minus119903NaBH
4
= minus119896 (119879) (3)
Equation (3) is formed as below when the integration isapplied
(119862NaBH40
minus 119862NaBH4
) = minus119896 (119879) sdot 119905 (4)
First-order reaction model is dependent on the reactantsrsquoconcentration and its basic (5) and integration applied forms(6) are shown below
119889119862NaBH4
119889119905= minus119903NaBH
4
= minus119896 (119879) sdot 119862NaBH4
(5)
ln(119862NaBH
40
119862NaBH4
) = 119896 (119879) sdot 119905 (6)
The second-order reaction model is also dependent onreactants concentration with second degree and integratedforms are shown below
119889119862NaBH4
119889119905= minus119903NaBH
4
= minus119896 (119879) sdot 1198622
NaBH4
(7)
(1
119862NaBH4
minus1
119862NaBH40
) = minus119896 (119879) sdot 119905 (8)
3 Results and Discussion
31 Sonochemical Approach to Coprecipitation Synthesis of Co-B Catalyst Co-B catalysts were synthesized via two differentsystems (Figure 1(a)) The CoB-1 catalyst was synthesizedwith sonochemical approach and CoB-2 which used as con-trol sample was synthesized bymagnetic stirring systemThecatalysts were codded according to their synthesis methods(Table 1)
Table 1 shows the textural properties of Co-B catalystsComparing the specific surface areas of CoB-1 catalyst withCoB-2 catalyst the sonochemical approach a considerablyincreased the surface area of catalyst up to 70 With thismethod not only specific surface area increased but also other
4 Journal of Chemistry
(a)
(b)
Figure 2 The SEM images of Co-B catalysts with times1000 (left) and times5000 (right) magnification (a) CoB-1 catalyst (b) CoB-2 catalyst
Table 2 Particle size distribution of Co-B catalysts
CodeAverage particle
size(120583m)
Maximumparticle size
(120583m)
Minimumparticle size
(120583m)CoB-1 125 277 030CoB-2 300 739 057
texture properties as pore size and volume of catalysts wereimproved up to 114 and 26 respectively
Figure 2 shows the SEM images of Co-B catalysts at1000 and 5000 magnification Particles of Co-B catalystsynthesized by sonochemical approach were homogeneouslydispersed and smaller than coprecipitation synthesized Co-Bcatalyst
Table 2 shows average minimum andmaximum particlesizes were measured from SEM images It was indicated thatCo-B prepared with sonochemical coprecipitation synthesiswas shown a smaller average size of 125 120583m and particle sizeof the catalyst was reduced up to 58 (Table 2) BET resultswere consistent with the SEM results
Figure 3 shows XRD patterns of synthesized Co-B cata-lysts Comparing XRD pattern of synthesized catalysts withthe standard diffraction spectrum (JCPDS 00-012-0443 and01-073-1540) the synthesized product was crystalline Co
3B
and Co3(BO3)2 The sharpness of XRD reflections clearly
050
100150200250300350
5 17 29 41 53 65 77 89
Cou
nts
CoB-1CoB-2
JPCDS 00-012-0443JPCDS 01-073-1540
ΔΔΔ
lowast
lowastlowastlowastlowastlowast
ΔΔ
ΔΔ
Δ
Δ
ΔΔ Δ
ΔΔ
Δ ΔΔΔΔ
Δ
lowast
2120579 (∘)
CoB3
Co3(BO3)2
Figure 3 The XRD patterns of Co-B catalysts
shows that the synthesized Co-B catalysts were highly crys-talline The characteristic peaks of phases were indexed inXRD patterns It was clear that sonochemical treatment doesnot affect the crystalline phases of Co-B catalysts
Figure 4 shows FT-IR spectrums of Co-B catalysts In adirect comparison of the observed FT-IR spectrums of bothcatalysts it was clearly seen that B-O band frequencies weredetected at the same wave number regions The bands at3197 cmminus1 and 3206 cmminus1 corresponded to vibration of H-O groups The bands at 1403 cmminus1 and 1350ndash935 cmminus1 werecontributed asymmetric stretching of B-O The bands were
Journal of Chemistry 5
0
20
40
60
80
100
120
650 1150 1650 2150 2650 3150 3650Wavenumber
CoB-2CoB-1
T(
)
(cmminus1)
Figure 4 The FT-IR spectrum of Co-B catalysts
0
20
40
60
80
0 5 10 15
Gen
erat
ed H
2vo
lum
e (m
L)
Time (min)
Alkaline sonohydrolysis
40∘C
60∘C
80∘C
NaBH4
(a)
Gen
erat
ed H
2vo
lum
e (m
L)
0
20
40
60
80
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysis
22∘C
40∘C
60∘C
NaBH4
(b)
Figure 5 Hydrogen generation volume versus time for sonohydrolysis and magnetic stirring hydrolysis of alkaline (10wt) 012 NaBH4
solutions in presence of 05mg CoB-1 catalyst
assigned between 950ndash870 cmminus1 and 710ndash795 cmminus1 and weresymmetric stretching band of B-O [28ndash30]
CoB-1 catalysts prepared via sonochemical coprecipita-tion synthesis show the best intrinsic and extrinsic propertiesthat are contributing factors to the catalytic activity Itwas concluded to start sonohydrolysis of alkaline NaBH
4
solutions with CoB-1 catalysts which were prepared viasonochemical coprecipitation synthesis
32 Sonochemical Approach to Hydrolysis of Alkaline NaBH4
Solutions In order to investigate the effect of sonochemicalapproach hydrolysis of alkaline NaBH
4solutions in presence
of CoB-1 catalyst were carried out with two different pro-cedures The evaluated H
2volume versus time during the
reactions was given in Figure 5 The H2generation started
immediately after catalyst contact with alkaline NaBH4solu-
tion As a result of this CoB-1 catalyst did not have inductionperiod to be active Effect of increasing in temperature wasshown in Figure 5TheH
2evolution shows direct proportion
with temperature in both systems In sonochemical alkalineNaBH
4solution hydrolysis hydrolysis time dropped 140min
from 941min by increasing of temperature from 22∘C to60∘C The same tendency was observed in magnetic stirringhydrolysis and reaction time decreased to 1388min
Figure 6 shows the effects of temperature and sono-waves on hydrogen generation It was clearly seen that bycomparing two different approach sono-waves developed thehydrolysis characteristics of system via cavitation on surfaceof catalystThe ultrasonic approach improved the interactionbetween the Co-B catalyst and alkaline NaBH
4solution
and made homogeneous distribution in the alkaline NaBH4
6 Journal of Chemistry
0
2000
4000
6000
8000
10000
40 60 80
Alkaline hydrolysis
SonohydrolysisMagnetic stirring hydrolysis
Temperature (∘C)
H2
gene
ratio
n ra
te (H
2ca
t)minus1
minus1
mL
min
gNaBH4
Figure 6Hydrogen generation rate comparison versus temperaturefor sonohydrolysis and magnetic stirring hydrolysis of alkaline(10wt) 012 NaBH
4solutions in presence of 05mg CoB-1 catalyst
solution and CoB-1 catalyst During the sonohydrolysiscavitation bubbles created high energy effects and this causedcontinuous acceleration of hydrogen generation rate [19]As can be seen ultrasonic treatment during the hydrolysisresults in maximum increase in the hydrogen generationfrom alkaline NaBH
4solution up to 65 at 40∘CThe authors
suggest to use of sonohydrolysis instead of magnetic stirringhydrolysis for improving the hydrogen generation rate ofsystem
Figure 7 shows the kinetic investigation of sonochemi-cal and magnetic stirring hydrolysis in presence of CoB-1catalyst The characterization of hydrolysis reaction behaviorwas identified by zero-order first-order and second-orderreaction kinetic models and Arrhenius theory As seen fromFigure 7 in both hydrolysis conditions the hydrolyses ofalkaline NaBH
4solutions were in compliance with zero-
order reaction kineticmodel and this indicated that hydrogengeneration rate was independent from concentration ofNaBH
4 Depending onArrhenius theory activation energy of
sonohydrolysis of alkalineNaBH4solutionwas 4615 kJsdotmolminus1
and its Arrhenius rate constant was 1989minminus1 For hydrol-ysis of alkaline NaBH
4solution which was carried out in
magnetic stirring systems the kinetic valueswere determinedas 5168 kJsdotmolminus1 activation energy and 1516minminus1 Arrheniusrate constant
In literature Co containing catalysts activation ener-gies were determined and summarized in Table 3 Theactivation energies of Co containing catalysts show vari-ety for example Copowder (7500 kJsdotmolminus1) Co-Raneyform (5370 kJsdotmolminus1) and active carbon supported Co-B(5780 kJsdotmolminus1) were relatively higher than our results whileCo nanoparticle (3500 kJsdotmolminus1) was lowerThe hydrolysis ofalkaline NaBH
4solution was carried out with sonochemical
approach the reaction kinetic was improved and value ofthem was decreased up to 12
Table 3 Activation energies in presence of various Co-basedcatalysts
Catalyst Activation energy(kJsdotmolminus1) References
Co powder 7500 [31]
Co nanoparticle 3500 [13]
Co (120572-Al2O3 support) 3263 [32]
Co (Raney form) 5370 [33]
Co-B (active carbon support) 5780 [34]
Co-B powder 6487 [12]
Co-B (clay support) 5632 [35]
Co-B 5273 [36]
CoB-1 (sonohydrolysis) 4615 At thiswork
CoB-1 (magnetic stirringhydrolysis) 5168 At this
work
4 Conclusion
In the present study sonochemical approach to coprecipi-tation synthesis of Co-B catalyst and hydrolysis of alkalineNaBH
4solutions was introducedThe following points result
from this studyThe sono-co-precipitation of CoCl
2sdot6H2O and B
2O3in
aqueous solution at pH 6 was proven to be a promisingprocedure in order to obtain Co-B crystalline catalyst withuniform 125 120583m particle size improved surface area andtexture properties On the other hand it was found that sono-chemical approach did not affect the crystalline structure andspectral properties of Co-B catalyst yet
The improving effect of sonochemical process on hydrol-ysis of alkaline NaBH
4solutions was approved when it
was compared with magnetic stirring system kinetic resultsHydrogen generation rate of alkaline NaBH
4solutions via
sonohydrolysis method in presence of CoB-1 catalyst hasshown enhanced influence at all temperatures Activationenergy as 4615 kJsdotmolminus1 of sonochemical coprecipitationsynthesized Co-B catalyst has compatible value comparedwith literature (32ndash75 kJsdotmolminus1) Rate law was formulized asgiven below
119903NaBH4
= 1989 sdot 119890minus4615RT (9)
As a result of this study the ultrasonicwaves improved theintrinsic and extrinsic properties of Co-B catalyst propertiesas specific surface area increased up to 70 particle sizedecreased up to 58 and hydrogen generation rate increasedup to 64 As can be seen sonochemical coprecipitationand sonohydrolysis proved to be promising techniques forsynthesis of Co-B catalyst and hydrolysis
Journal of Chemistry 7
000
002
004
006
008
010
012
014
0 5 10 15 20Time (min)
Alkaline sonohydrolysis Zero-order reaction kinetic
000
100
200
300
400
500
0 5 10 15 20Time (min)
Alkaline sonohydrolysis First-order reaction kinetic
000
10000
20000
30000
40000
50000
60000
0 5 10 15 20Time (min)
Alkaline sonohydrolysis Second-order reaction kinetic
000
002
004
006
008
010
012
014
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisZero-order reaction kinetic
000
100
200
300
400
500
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisFirst-order reaction kinetic
000
10000
20000
30000
40000
50000
60000
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisSecond-order reaction kinetic
Ln(C
CN
aBH
4)C
minusC
NaB
H4
(M)
Cminus
CN
aBH
4(M
)(1
CN
aBH
4)minus
(1C
)
22∘C
40∘C
60∘C
22∘C
40∘C
60∘C
NaBH4 NaBH4
NaBH4NaBH4
NaBH4 NaBH4
Ln(C
CN
aBH
4)
(1C
NaB
H4)minus
(1C
)
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
Figure 7The kinetic investigation the zero first and second reaction kinetic models for sonohydrolysis and magnetic stirring hydrolysis ofalkaline (10wt) 012M NaBH
4solutions
Symbols Used
119903 [H2molsdotminminus1sdotgminus1 cat] H
2generation rate
119864119886 [kJsdotmolminus1] Activation energy119877 [kJsdotmolminus1 sdot∘Cminus1] Gas constant119879 [∘C] Temperature
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
The authors would like to thank the Yildiz Technical Univer-sity Research Foundation (Project no 2012-07-01-YL02) forits financial support
References[1] S C Amendola S L Sharp-Goldman M S Janjua et al ldquoSafe
portable hydrogen gas generator using aqueous borohydridesolution and Ru catalystrdquo International Journal of HydrogenEnergy vol 25 no 10 pp 969ndash975 2000
8 Journal of Chemistry
[2] R Retnamma A Q Novais and C M Rangel ldquoKinetics ofhydrolysis of sodium borohydride for hydrogen productionin fuel cell applications a reviewrdquo International Journal ofHydrogen Energy vol 36 no 16 pp 9772ndash9790 2011
[3] O Akdim U B Demirci D Muller and P Miele ldquoCobalt(II) salts performing materials for generating hydrogen fromsodiumborohydriderdquo International Journal of Hydrogen Energyvol 34 no 6 pp 2631ndash2637 2009
[4] J Liang Y Li Y Huang et al ldquoSodium borohydride hydrolysison highly efficient Co-BPd catalystsrdquo International Journal ofHydrogen Energy vol 33 no 15 pp 4048ndash4054 2008
[5] U B Demirci O Akdim J Andrieux J Hannauer RChamoun and P Miele ldquoSodium borohydride hydrolysis ashydrogen generator Issues state of the art and applicabilityupstream froma fuel cellrdquo Fuel Cells vol 10 no 3 pp 335ndash3502010
[6] US Department of Energy Hydrogen Program 2007httpwwwhydrogenenergygov
[7] U B Demirci and P Miele ldquoSodium borohydride versusammonia borane in hydrogen storage and direct fuel cellapplicationsrdquo Energy and Environmental Science vol 2 no 6pp 627ndash637 2009
[8] B H Liu and Z P Li ldquoA review Hydrogen generation fromborohydride hydrolysis reactionrdquo Journal of Power Sources vol187 no 2 pp 527ndash534 2009
[9] S Cavaliere J Hannauer U B Demirci O Akdim and PMieleldquoEx situ characterization of N
2H4- NaBH
4- and NH
3BH3-
reduced cobalt catalysts used in NaBH4hydrolysisrdquo Catalysis
Today vol 170 no 1 pp 3ndash12 2011[10] H I Schlesinger E R Brown A E Finholitam J R Gilbreathh
H R Hoekstra and E A Hyde ldquoProcedures for the preparationof methyl boraterdquo Journal of American Chemical Society vol 75no 1 pp 213ndash215 1953
[11] A M Ozerova V I Simagina O V Komova et al ldquoCobaltborate catalysts for hydrogen production via hydrolysis ofsodium borohydriderdquo Journal of Alloys and Compounds vol513 pp 266ndash272 2012
[12] S U Jeong R K Kim E A Cho et al ldquoA study on hydrogengeneration from NaBH
4solution using the high-performance
Co-B catalystrdquo Journal of Power Sources vol 144 no 1 pp 129ndash134 2005
[13] R Khan S W Kim T-J Kim and C-M Nam ldquoComparativestudy of the photocatalytic performance of boron-iron Co-doped and boron-doped TiO
2nanoparticlesrdquoMaterials Chem-
istry and Physics vol 112 no 1 pp 167ndash172 2008[14] A Kanturk Figen and B Coskuner ldquoA novel perspective for
hydrogen generation from ammonia borane (NH3BH3) with
Co-B catalysts lsquoultrasonic Hydrolysisrsquordquo International Journal ofHydrogen Energy vol 38 no 6 pp 2824ndash2835 2013
[15] C C Yang M S Chen and Y W Chen ldquoHydrogen generationby hydrolysis of sodium borohydride on CoBSiO
2catalystrdquo
International Journal ofHydrogenEnergy vol 36 no 2 pp 1418ndash1423 2011
[16] R Patil P Bhoir P Deshpande T Wattamwar M Shirude andP Chaskar ldquoRelevance of sonochemistry or ultrasound (US)as a proficient means for the synthesis of fused heterocyclesrdquoUltrasonics Sonochemistry vol 20 no 6 pp 1327ndash1336 2013
[17] T Q Liu O Sakurai N Mizutani and M Kato ldquoPreparationof spherical fine ZnO particles by the spray pyrolysis methodusing ultrasonic atomization techniquesrdquo Journal of MaterialsScience vol 21 no 10 pp 3698ndash3702 1986
[18] S L Che K Takada K Takashima O Sakurai K Shinozakiand N Mizutani ldquoPreparation of dense spherical Ni particlesand hollow NiO particles by spray pyrolysisrdquo Journal of Materi-als Science vol 34 no 6 pp 1313ndash1318 1999
[19] C L Bianchi E Gotti L Toscano and V Ragaini ldquoPreparationof PdC catalysts via ultrasound a study of the metal distribu-tionrdquo Ultrasonics Sonochemistry vol 4 no 4 pp 317ndash320 1997
[20] S S Ostapenko L Jastrzebski J Lagowski and B SoporildquoIncreasing short minority carrier diffusion lengths in solar-grade polycrystalline silicon by ultrasound treatmentrdquo AppliedPhysics Letters vol 65 no 12 pp 1555ndash1557 1994
[21] M Run SWu andGWu ldquoUltrasonic synthesis ofmesoporousmolecular sieverdquo Microporous and Mesoporous Materials vol74 no 1-3 pp 37ndash47 2004
[22] U R Pillai E Sahle-Demessie and R S Varma ldquoAlterna-tive routes for catalyst preparation use of ultrasound andmicrowave irradiation for the preparation of vanadium phos-phorus oxide catalyst and their activity for hydrocarbon oxida-tionrdquo Applied Catalysis A General vol 252 no 1 pp 1ndash8 2003
[23] H LiH Li J ZhangWDai andMQiao ldquoUltrasound-assistedpreparation of a highly active and selective Co-B amorphousalloy catalyst in uniform spherical nanoparticlesrdquo Journal ofCatalysis vol 246 no 2 pp 301ndash307 2007
[24] M G Sulman ldquoEffects of ultrasound on catalytic processesrdquoRussian Chemical Reviews vol 69 no 2 pp 165ndash177 2000
[25] H Li J Zhang and H Li ldquoUltrasound-assisted preparationof a novel Ni-B amorphous catalyst in uniform nanoparticlesfor p-chloronitrobenzene hydrogenationrdquo Catalysis Communi-cations vol 8 no 12 pp 2212ndash2216 2007
[26] A J Hung S F Tsai Y Y Hsu J R Ku Y H Chen and CC Yu ldquoKinetics of sodium borohydride hydrolysis reaction forhydrogen generationrdquo International Journal ofHydrogen Energyvol 33 no 21 pp 6205ndash6215 2008
[27] O Levenspiel Chemical Reaction Engineering John Wiley ampSons New York NY USA 3rd edition 1999
[28] L Jun X Shuping and G Shiyang ldquoFT-IR and Ramanspectroscopic study of hydrated boratesrdquo Spectrochimica ActaA Molecular Spectroscopy vol 51 no 4 pp 519ndash532 1995
[29] A Kanturk M Sari and S Piskin ldquoSynthesis crystal structureand dehydration kinetics of NaB(OH)
4sdot2H2Ordquo Korean Journal
of Chemical Engineering vol 25 no 6 pp 1331ndash1337 2008[30] Q Zhang Y Wu X Sun and J Ortega ldquoKinetics of catalytic
hydrolysis of stabilized sodium borohydride solutionsrdquo Indus-trial and Engineering Chemistry Research vol 46 no 4 pp1120ndash1124 2007
[31] J Andrieux D Swierczynski L Laversenne et al ldquoAmultifactorstudy of catalyzed hydrolysis of solidNaBH
4on cobalt nanopar-
ticles thermodynamics and kineticsrdquo International Journal ofHydrogen Energy vol 34 no 2 pp 938ndash951 2009
[32] B H Liu Z P Li and S Suda ldquoNickel- and cobalt-basedcatalysts for hydrogen generation by hydrolysis of borohydriderdquoJournal of Alloys and Compounds vol 415 no 1-2 pp 288ndash2932006
[33] W Ye H Zhang D Xu L Ma and B Yi ldquoHydrogen generationutilizing alkaline sodium borohydride solution and supportedcobalt catalystrdquo Journal of Power Sources vol 164 no 2 pp 544ndash548 2007
[34] J Zhao H Ma and J Chen ldquoImproved hydrogen generationfrom alkaline image solution using carbon-supported image ascatalystsrdquo International Journal of Hydrogen Energy vol 32 no18 pp 4711ndash4716 2007
Journal of Chemistry 9
[35] H Tian Q Guo and D Xu ldquoHydrogen generation fromcatalytic hydrolysis of alkaline sodium borohydride solutionusing attapulgite clay-supported Co-B catalystrdquo Journal ofPower Sources vol 195 no 8 pp 2136ndash2142 2010
[36] C H Liu B H Chen C L Hsueh J R Ku M S Jeng and FTsau ldquoHydrogen generation from hydrolysis of sodium boro-hydride using Ni-Ru nanocomposite as catalystsrdquo InternationalJournal of Hydrogen Energy vol 34 no 5 pp 2153ndash2163 2009
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Journal of Chemistry 3
Table 1 Texture properties of Co-B catalysts
Code Synthesis type Specific surface area (m2g) Pore size (cm3g) Pore volume (A)CoB-1 sono-coprecipitation 336 plusmn 016 00141 16867CoB-2 Coprecipitation 198 plusmn 011 00066 13339
NH4OH addition the synthesis reaction occurred as (1) The
coprecipitation synthesis reaction of Co-B compounds aregiven as below
9Co2+ + 2B2O3
Alkali medium997888997888997888997888997888997888997888997888997888997888rarr 2Co
3B + Co
3(BO3)2 (1)
Subsequently bulk materials were dried at approximately100∘C under the vacuum condition for overnight to eliminatethe remaining water molecules Moreover forming stablestructure catalysts were calcined at 500∘C for 4 hours in airAs a last step Co-B catalysts were prepared for characteriza-tion of the intrinsic and extrinsic properties
XRD patterns of Co-B catalysts were recorded usingPhilips Panalytical XrsquoPert-Pro diffractometer with Cu K120572radiation in a range of diffraction angles from 5∘ to 80∘ withCu K120572 radiation (120582 = 015418mm) at operating parametersof 40mA and 45 kV with 002∘ step size and speed of 1∘minThe morphology and particular size of the Co-B catalystswere observed by using SEM techniques (JEOL JSM 5410LV) The catalysts were covered with Au and made readyfor analysis by fixing to the devicersquos sample holder withthe help of a carbon sticky band Surface properties of Co-B catalysts were determined via using a surface area andporosimetry analyzer (Micromeritics ASAP 2020) Spectralproperties were characterized via FT-IR (Perkin Elmer Spec-trum One) with ATR accessories in the spectral range of4000 cmminus1ndash650 cmminus1 with a spectral resolution of 4 cmminus1 inthe transmittance mode
22 Sonochemical Approach to Hydrolysis of Alkaline NaBH4
Solutions The hydrolysis reaction of NaBH4is as given
below Four mole H2is generated during efficient hydrolysis
reaction per mole NaBH4[1ndash3]
NaBH4+ 2H2O 997888rarr NaBO
2+ 4H2 (2)
Figure 1(b) shows the systems the hydrolysis reactions ofalkaline NaBH
4solutions were carried out The 15mL glass
reactor was immersed in a system and connected to thewater filled inverter burette in order to measure the evolvedhydrogen volume The measured data was used in inves-tigation of hydrolysis kinetic To compare the results ofsonochemical hydrolysis the systemmodified with magneticstirrer and the same procedure was followed for magneticstirring (500 rpm) According to the procedure ultrasonica-tor or magnetic stirring was applied during the hydrolysis ofalkaline NaBH
4solutions
In the experiments 10 wt NaOH alkaline 012MNaBH
4was hydrolyzed in presence of 05mg catalysts The
reactions applied in range of 22∘Cndash60∘C with temperaturecontrolling system
The kinetic investigation of sonochemical and magneticstirring hydrolysis of alkaline NaBH
4solution was identified
via Arrhenius theory The characterization of hydrolysisreaction behavior was enlightened by zero-order first-orderand second-order reaction kinetic models The activationenergies and rate constants were determined via Arrheniustheory [12 26 27]
In literature zero-order reaction is shown as belowmodelgenerally defined as reactant independent kinetic modelIn the model 119862NaBH
4
is the concentration 119903 is the rate ofreaction and 119896 is the reaction rate constant based on thesolution volume
119889119862NaBH4
119889119905= minus119903NaBH
4
= minus119896 (119879) (3)
Equation (3) is formed as below when the integration isapplied
(119862NaBH40
minus 119862NaBH4
) = minus119896 (119879) sdot 119905 (4)
First-order reaction model is dependent on the reactantsrsquoconcentration and its basic (5) and integration applied forms(6) are shown below
119889119862NaBH4
119889119905= minus119903NaBH
4
= minus119896 (119879) sdot 119862NaBH4
(5)
ln(119862NaBH
40
119862NaBH4
) = 119896 (119879) sdot 119905 (6)
The second-order reaction model is also dependent onreactants concentration with second degree and integratedforms are shown below
119889119862NaBH4
119889119905= minus119903NaBH
4
= minus119896 (119879) sdot 1198622
NaBH4
(7)
(1
119862NaBH4
minus1
119862NaBH40
) = minus119896 (119879) sdot 119905 (8)
3 Results and Discussion
31 Sonochemical Approach to Coprecipitation Synthesis of Co-B Catalyst Co-B catalysts were synthesized via two differentsystems (Figure 1(a)) The CoB-1 catalyst was synthesizedwith sonochemical approach and CoB-2 which used as con-trol sample was synthesized bymagnetic stirring systemThecatalysts were codded according to their synthesis methods(Table 1)
Table 1 shows the textural properties of Co-B catalystsComparing the specific surface areas of CoB-1 catalyst withCoB-2 catalyst the sonochemical approach a considerablyincreased the surface area of catalyst up to 70 With thismethod not only specific surface area increased but also other
4 Journal of Chemistry
(a)
(b)
Figure 2 The SEM images of Co-B catalysts with times1000 (left) and times5000 (right) magnification (a) CoB-1 catalyst (b) CoB-2 catalyst
Table 2 Particle size distribution of Co-B catalysts
CodeAverage particle
size(120583m)
Maximumparticle size
(120583m)
Minimumparticle size
(120583m)CoB-1 125 277 030CoB-2 300 739 057
texture properties as pore size and volume of catalysts wereimproved up to 114 and 26 respectively
Figure 2 shows the SEM images of Co-B catalysts at1000 and 5000 magnification Particles of Co-B catalystsynthesized by sonochemical approach were homogeneouslydispersed and smaller than coprecipitation synthesized Co-Bcatalyst
Table 2 shows average minimum andmaximum particlesizes were measured from SEM images It was indicated thatCo-B prepared with sonochemical coprecipitation synthesiswas shown a smaller average size of 125 120583m and particle sizeof the catalyst was reduced up to 58 (Table 2) BET resultswere consistent with the SEM results
Figure 3 shows XRD patterns of synthesized Co-B cata-lysts Comparing XRD pattern of synthesized catalysts withthe standard diffraction spectrum (JCPDS 00-012-0443 and01-073-1540) the synthesized product was crystalline Co
3B
and Co3(BO3)2 The sharpness of XRD reflections clearly
050
100150200250300350
5 17 29 41 53 65 77 89
Cou
nts
CoB-1CoB-2
JPCDS 00-012-0443JPCDS 01-073-1540
ΔΔΔ
lowast
lowastlowastlowastlowastlowast
ΔΔ
ΔΔ
Δ
Δ
ΔΔ Δ
ΔΔ
Δ ΔΔΔΔ
Δ
lowast
2120579 (∘)
CoB3
Co3(BO3)2
Figure 3 The XRD patterns of Co-B catalysts
shows that the synthesized Co-B catalysts were highly crys-talline The characteristic peaks of phases were indexed inXRD patterns It was clear that sonochemical treatment doesnot affect the crystalline phases of Co-B catalysts
Figure 4 shows FT-IR spectrums of Co-B catalysts In adirect comparison of the observed FT-IR spectrums of bothcatalysts it was clearly seen that B-O band frequencies weredetected at the same wave number regions The bands at3197 cmminus1 and 3206 cmminus1 corresponded to vibration of H-O groups The bands at 1403 cmminus1 and 1350ndash935 cmminus1 werecontributed asymmetric stretching of B-O The bands were
Journal of Chemistry 5
0
20
40
60
80
100
120
650 1150 1650 2150 2650 3150 3650Wavenumber
CoB-2CoB-1
T(
)
(cmminus1)
Figure 4 The FT-IR spectrum of Co-B catalysts
0
20
40
60
80
0 5 10 15
Gen
erat
ed H
2vo
lum
e (m
L)
Time (min)
Alkaline sonohydrolysis
40∘C
60∘C
80∘C
NaBH4
(a)
Gen
erat
ed H
2vo
lum
e (m
L)
0
20
40
60
80
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysis
22∘C
40∘C
60∘C
NaBH4
(b)
Figure 5 Hydrogen generation volume versus time for sonohydrolysis and magnetic stirring hydrolysis of alkaline (10wt) 012 NaBH4
solutions in presence of 05mg CoB-1 catalyst
assigned between 950ndash870 cmminus1 and 710ndash795 cmminus1 and weresymmetric stretching band of B-O [28ndash30]
CoB-1 catalysts prepared via sonochemical coprecipita-tion synthesis show the best intrinsic and extrinsic propertiesthat are contributing factors to the catalytic activity Itwas concluded to start sonohydrolysis of alkaline NaBH
4
solutions with CoB-1 catalysts which were prepared viasonochemical coprecipitation synthesis
32 Sonochemical Approach to Hydrolysis of Alkaline NaBH4
Solutions In order to investigate the effect of sonochemicalapproach hydrolysis of alkaline NaBH
4solutions in presence
of CoB-1 catalyst were carried out with two different pro-cedures The evaluated H
2volume versus time during the
reactions was given in Figure 5 The H2generation started
immediately after catalyst contact with alkaline NaBH4solu-
tion As a result of this CoB-1 catalyst did not have inductionperiod to be active Effect of increasing in temperature wasshown in Figure 5TheH
2evolution shows direct proportion
with temperature in both systems In sonochemical alkalineNaBH
4solution hydrolysis hydrolysis time dropped 140min
from 941min by increasing of temperature from 22∘C to60∘C The same tendency was observed in magnetic stirringhydrolysis and reaction time decreased to 1388min
Figure 6 shows the effects of temperature and sono-waves on hydrogen generation It was clearly seen that bycomparing two different approach sono-waves developed thehydrolysis characteristics of system via cavitation on surfaceof catalystThe ultrasonic approach improved the interactionbetween the Co-B catalyst and alkaline NaBH
4solution
and made homogeneous distribution in the alkaline NaBH4
6 Journal of Chemistry
0
2000
4000
6000
8000
10000
40 60 80
Alkaline hydrolysis
SonohydrolysisMagnetic stirring hydrolysis
Temperature (∘C)
H2
gene
ratio
n ra
te (H
2ca
t)minus1
minus1
mL
min
gNaBH4
Figure 6Hydrogen generation rate comparison versus temperaturefor sonohydrolysis and magnetic stirring hydrolysis of alkaline(10wt) 012 NaBH
4solutions in presence of 05mg CoB-1 catalyst
solution and CoB-1 catalyst During the sonohydrolysiscavitation bubbles created high energy effects and this causedcontinuous acceleration of hydrogen generation rate [19]As can be seen ultrasonic treatment during the hydrolysisresults in maximum increase in the hydrogen generationfrom alkaline NaBH
4solution up to 65 at 40∘CThe authors
suggest to use of sonohydrolysis instead of magnetic stirringhydrolysis for improving the hydrogen generation rate ofsystem
Figure 7 shows the kinetic investigation of sonochemi-cal and magnetic stirring hydrolysis in presence of CoB-1catalyst The characterization of hydrolysis reaction behaviorwas identified by zero-order first-order and second-orderreaction kinetic models and Arrhenius theory As seen fromFigure 7 in both hydrolysis conditions the hydrolyses ofalkaline NaBH
4solutions were in compliance with zero-
order reaction kineticmodel and this indicated that hydrogengeneration rate was independent from concentration ofNaBH
4 Depending onArrhenius theory activation energy of
sonohydrolysis of alkalineNaBH4solutionwas 4615 kJsdotmolminus1
and its Arrhenius rate constant was 1989minminus1 For hydrol-ysis of alkaline NaBH
4solution which was carried out in
magnetic stirring systems the kinetic valueswere determinedas 5168 kJsdotmolminus1 activation energy and 1516minminus1 Arrheniusrate constant
In literature Co containing catalysts activation ener-gies were determined and summarized in Table 3 Theactivation energies of Co containing catalysts show vari-ety for example Copowder (7500 kJsdotmolminus1) Co-Raneyform (5370 kJsdotmolminus1) and active carbon supported Co-B(5780 kJsdotmolminus1) were relatively higher than our results whileCo nanoparticle (3500 kJsdotmolminus1) was lowerThe hydrolysis ofalkaline NaBH
4solution was carried out with sonochemical
approach the reaction kinetic was improved and value ofthem was decreased up to 12
Table 3 Activation energies in presence of various Co-basedcatalysts
Catalyst Activation energy(kJsdotmolminus1) References
Co powder 7500 [31]
Co nanoparticle 3500 [13]
Co (120572-Al2O3 support) 3263 [32]
Co (Raney form) 5370 [33]
Co-B (active carbon support) 5780 [34]
Co-B powder 6487 [12]
Co-B (clay support) 5632 [35]
Co-B 5273 [36]
CoB-1 (sonohydrolysis) 4615 At thiswork
CoB-1 (magnetic stirringhydrolysis) 5168 At this
work
4 Conclusion
In the present study sonochemical approach to coprecipi-tation synthesis of Co-B catalyst and hydrolysis of alkalineNaBH
4solutions was introducedThe following points result
from this studyThe sono-co-precipitation of CoCl
2sdot6H2O and B
2O3in
aqueous solution at pH 6 was proven to be a promisingprocedure in order to obtain Co-B crystalline catalyst withuniform 125 120583m particle size improved surface area andtexture properties On the other hand it was found that sono-chemical approach did not affect the crystalline structure andspectral properties of Co-B catalyst yet
The improving effect of sonochemical process on hydrol-ysis of alkaline NaBH
4solutions was approved when it
was compared with magnetic stirring system kinetic resultsHydrogen generation rate of alkaline NaBH
4solutions via
sonohydrolysis method in presence of CoB-1 catalyst hasshown enhanced influence at all temperatures Activationenergy as 4615 kJsdotmolminus1 of sonochemical coprecipitationsynthesized Co-B catalyst has compatible value comparedwith literature (32ndash75 kJsdotmolminus1) Rate law was formulized asgiven below
119903NaBH4
= 1989 sdot 119890minus4615RT (9)
As a result of this study the ultrasonicwaves improved theintrinsic and extrinsic properties of Co-B catalyst propertiesas specific surface area increased up to 70 particle sizedecreased up to 58 and hydrogen generation rate increasedup to 64 As can be seen sonochemical coprecipitationand sonohydrolysis proved to be promising techniques forsynthesis of Co-B catalyst and hydrolysis
Journal of Chemistry 7
000
002
004
006
008
010
012
014
0 5 10 15 20Time (min)
Alkaline sonohydrolysis Zero-order reaction kinetic
000
100
200
300
400
500
0 5 10 15 20Time (min)
Alkaline sonohydrolysis First-order reaction kinetic
000
10000
20000
30000
40000
50000
60000
0 5 10 15 20Time (min)
Alkaline sonohydrolysis Second-order reaction kinetic
000
002
004
006
008
010
012
014
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisZero-order reaction kinetic
000
100
200
300
400
500
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisFirst-order reaction kinetic
000
10000
20000
30000
40000
50000
60000
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisSecond-order reaction kinetic
Ln(C
CN
aBH
4)C
minusC
NaB
H4
(M)
Cminus
CN
aBH
4(M
)(1
CN
aBH
4)minus
(1C
)
22∘C
40∘C
60∘C
22∘C
40∘C
60∘C
NaBH4 NaBH4
NaBH4NaBH4
NaBH4 NaBH4
Ln(C
CN
aBH
4)
(1C
NaB
H4)minus
(1C
)
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
Figure 7The kinetic investigation the zero first and second reaction kinetic models for sonohydrolysis and magnetic stirring hydrolysis ofalkaline (10wt) 012M NaBH
4solutions
Symbols Used
119903 [H2molsdotminminus1sdotgminus1 cat] H
2generation rate
119864119886 [kJsdotmolminus1] Activation energy119877 [kJsdotmolminus1 sdot∘Cminus1] Gas constant119879 [∘C] Temperature
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
The authors would like to thank the Yildiz Technical Univer-sity Research Foundation (Project no 2012-07-01-YL02) forits financial support
References[1] S C Amendola S L Sharp-Goldman M S Janjua et al ldquoSafe
portable hydrogen gas generator using aqueous borohydridesolution and Ru catalystrdquo International Journal of HydrogenEnergy vol 25 no 10 pp 969ndash975 2000
8 Journal of Chemistry
[2] R Retnamma A Q Novais and C M Rangel ldquoKinetics ofhydrolysis of sodium borohydride for hydrogen productionin fuel cell applications a reviewrdquo International Journal ofHydrogen Energy vol 36 no 16 pp 9772ndash9790 2011
[3] O Akdim U B Demirci D Muller and P Miele ldquoCobalt(II) salts performing materials for generating hydrogen fromsodiumborohydriderdquo International Journal of Hydrogen Energyvol 34 no 6 pp 2631ndash2637 2009
[4] J Liang Y Li Y Huang et al ldquoSodium borohydride hydrolysison highly efficient Co-BPd catalystsrdquo International Journal ofHydrogen Energy vol 33 no 15 pp 4048ndash4054 2008
[5] U B Demirci O Akdim J Andrieux J Hannauer RChamoun and P Miele ldquoSodium borohydride hydrolysis ashydrogen generator Issues state of the art and applicabilityupstream froma fuel cellrdquo Fuel Cells vol 10 no 3 pp 335ndash3502010
[6] US Department of Energy Hydrogen Program 2007httpwwwhydrogenenergygov
[7] U B Demirci and P Miele ldquoSodium borohydride versusammonia borane in hydrogen storage and direct fuel cellapplicationsrdquo Energy and Environmental Science vol 2 no 6pp 627ndash637 2009
[8] B H Liu and Z P Li ldquoA review Hydrogen generation fromborohydride hydrolysis reactionrdquo Journal of Power Sources vol187 no 2 pp 527ndash534 2009
[9] S Cavaliere J Hannauer U B Demirci O Akdim and PMieleldquoEx situ characterization of N
2H4- NaBH
4- and NH
3BH3-
reduced cobalt catalysts used in NaBH4hydrolysisrdquo Catalysis
Today vol 170 no 1 pp 3ndash12 2011[10] H I Schlesinger E R Brown A E Finholitam J R Gilbreathh
H R Hoekstra and E A Hyde ldquoProcedures for the preparationof methyl boraterdquo Journal of American Chemical Society vol 75no 1 pp 213ndash215 1953
[11] A M Ozerova V I Simagina O V Komova et al ldquoCobaltborate catalysts for hydrogen production via hydrolysis ofsodium borohydriderdquo Journal of Alloys and Compounds vol513 pp 266ndash272 2012
[12] S U Jeong R K Kim E A Cho et al ldquoA study on hydrogengeneration from NaBH
4solution using the high-performance
Co-B catalystrdquo Journal of Power Sources vol 144 no 1 pp 129ndash134 2005
[13] R Khan S W Kim T-J Kim and C-M Nam ldquoComparativestudy of the photocatalytic performance of boron-iron Co-doped and boron-doped TiO
2nanoparticlesrdquoMaterials Chem-
istry and Physics vol 112 no 1 pp 167ndash172 2008[14] A Kanturk Figen and B Coskuner ldquoA novel perspective for
hydrogen generation from ammonia borane (NH3BH3) with
Co-B catalysts lsquoultrasonic Hydrolysisrsquordquo International Journal ofHydrogen Energy vol 38 no 6 pp 2824ndash2835 2013
[15] C C Yang M S Chen and Y W Chen ldquoHydrogen generationby hydrolysis of sodium borohydride on CoBSiO
2catalystrdquo
International Journal ofHydrogenEnergy vol 36 no 2 pp 1418ndash1423 2011
[16] R Patil P Bhoir P Deshpande T Wattamwar M Shirude andP Chaskar ldquoRelevance of sonochemistry or ultrasound (US)as a proficient means for the synthesis of fused heterocyclesrdquoUltrasonics Sonochemistry vol 20 no 6 pp 1327ndash1336 2013
[17] T Q Liu O Sakurai N Mizutani and M Kato ldquoPreparationof spherical fine ZnO particles by the spray pyrolysis methodusing ultrasonic atomization techniquesrdquo Journal of MaterialsScience vol 21 no 10 pp 3698ndash3702 1986
[18] S L Che K Takada K Takashima O Sakurai K Shinozakiand N Mizutani ldquoPreparation of dense spherical Ni particlesand hollow NiO particles by spray pyrolysisrdquo Journal of Materi-als Science vol 34 no 6 pp 1313ndash1318 1999
[19] C L Bianchi E Gotti L Toscano and V Ragaini ldquoPreparationof PdC catalysts via ultrasound a study of the metal distribu-tionrdquo Ultrasonics Sonochemistry vol 4 no 4 pp 317ndash320 1997
[20] S S Ostapenko L Jastrzebski J Lagowski and B SoporildquoIncreasing short minority carrier diffusion lengths in solar-grade polycrystalline silicon by ultrasound treatmentrdquo AppliedPhysics Letters vol 65 no 12 pp 1555ndash1557 1994
[21] M Run SWu andGWu ldquoUltrasonic synthesis ofmesoporousmolecular sieverdquo Microporous and Mesoporous Materials vol74 no 1-3 pp 37ndash47 2004
[22] U R Pillai E Sahle-Demessie and R S Varma ldquoAlterna-tive routes for catalyst preparation use of ultrasound andmicrowave irradiation for the preparation of vanadium phos-phorus oxide catalyst and their activity for hydrocarbon oxida-tionrdquo Applied Catalysis A General vol 252 no 1 pp 1ndash8 2003
[23] H LiH Li J ZhangWDai andMQiao ldquoUltrasound-assistedpreparation of a highly active and selective Co-B amorphousalloy catalyst in uniform spherical nanoparticlesrdquo Journal ofCatalysis vol 246 no 2 pp 301ndash307 2007
[24] M G Sulman ldquoEffects of ultrasound on catalytic processesrdquoRussian Chemical Reviews vol 69 no 2 pp 165ndash177 2000
[25] H Li J Zhang and H Li ldquoUltrasound-assisted preparationof a novel Ni-B amorphous catalyst in uniform nanoparticlesfor p-chloronitrobenzene hydrogenationrdquo Catalysis Communi-cations vol 8 no 12 pp 2212ndash2216 2007
[26] A J Hung S F Tsai Y Y Hsu J R Ku Y H Chen and CC Yu ldquoKinetics of sodium borohydride hydrolysis reaction forhydrogen generationrdquo International Journal ofHydrogen Energyvol 33 no 21 pp 6205ndash6215 2008
[27] O Levenspiel Chemical Reaction Engineering John Wiley ampSons New York NY USA 3rd edition 1999
[28] L Jun X Shuping and G Shiyang ldquoFT-IR and Ramanspectroscopic study of hydrated boratesrdquo Spectrochimica ActaA Molecular Spectroscopy vol 51 no 4 pp 519ndash532 1995
[29] A Kanturk M Sari and S Piskin ldquoSynthesis crystal structureand dehydration kinetics of NaB(OH)
4sdot2H2Ordquo Korean Journal
of Chemical Engineering vol 25 no 6 pp 1331ndash1337 2008[30] Q Zhang Y Wu X Sun and J Ortega ldquoKinetics of catalytic
hydrolysis of stabilized sodium borohydride solutionsrdquo Indus-trial and Engineering Chemistry Research vol 46 no 4 pp1120ndash1124 2007
[31] J Andrieux D Swierczynski L Laversenne et al ldquoAmultifactorstudy of catalyzed hydrolysis of solidNaBH
4on cobalt nanopar-
ticles thermodynamics and kineticsrdquo International Journal ofHydrogen Energy vol 34 no 2 pp 938ndash951 2009
[32] B H Liu Z P Li and S Suda ldquoNickel- and cobalt-basedcatalysts for hydrogen generation by hydrolysis of borohydriderdquoJournal of Alloys and Compounds vol 415 no 1-2 pp 288ndash2932006
[33] W Ye H Zhang D Xu L Ma and B Yi ldquoHydrogen generationutilizing alkaline sodium borohydride solution and supportedcobalt catalystrdquo Journal of Power Sources vol 164 no 2 pp 544ndash548 2007
[34] J Zhao H Ma and J Chen ldquoImproved hydrogen generationfrom alkaline image solution using carbon-supported image ascatalystsrdquo International Journal of Hydrogen Energy vol 32 no18 pp 4711ndash4716 2007
Journal of Chemistry 9
[35] H Tian Q Guo and D Xu ldquoHydrogen generation fromcatalytic hydrolysis of alkaline sodium borohydride solutionusing attapulgite clay-supported Co-B catalystrdquo Journal ofPower Sources vol 195 no 8 pp 2136ndash2142 2010
[36] C H Liu B H Chen C L Hsueh J R Ku M S Jeng and FTsau ldquoHydrogen generation from hydrolysis of sodium boro-hydride using Ni-Ru nanocomposite as catalystsrdquo InternationalJournal of Hydrogen Energy vol 34 no 5 pp 2153ndash2163 2009
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
4 Journal of Chemistry
(a)
(b)
Figure 2 The SEM images of Co-B catalysts with times1000 (left) and times5000 (right) magnification (a) CoB-1 catalyst (b) CoB-2 catalyst
Table 2 Particle size distribution of Co-B catalysts
CodeAverage particle
size(120583m)
Maximumparticle size
(120583m)
Minimumparticle size
(120583m)CoB-1 125 277 030CoB-2 300 739 057
texture properties as pore size and volume of catalysts wereimproved up to 114 and 26 respectively
Figure 2 shows the SEM images of Co-B catalysts at1000 and 5000 magnification Particles of Co-B catalystsynthesized by sonochemical approach were homogeneouslydispersed and smaller than coprecipitation synthesized Co-Bcatalyst
Table 2 shows average minimum andmaximum particlesizes were measured from SEM images It was indicated thatCo-B prepared with sonochemical coprecipitation synthesiswas shown a smaller average size of 125 120583m and particle sizeof the catalyst was reduced up to 58 (Table 2) BET resultswere consistent with the SEM results
Figure 3 shows XRD patterns of synthesized Co-B cata-lysts Comparing XRD pattern of synthesized catalysts withthe standard diffraction spectrum (JCPDS 00-012-0443 and01-073-1540) the synthesized product was crystalline Co
3B
and Co3(BO3)2 The sharpness of XRD reflections clearly
050
100150200250300350
5 17 29 41 53 65 77 89
Cou
nts
CoB-1CoB-2
JPCDS 00-012-0443JPCDS 01-073-1540
ΔΔΔ
lowast
lowastlowastlowastlowastlowast
ΔΔ
ΔΔ
Δ
Δ
ΔΔ Δ
ΔΔ
Δ ΔΔΔΔ
Δ
lowast
2120579 (∘)
CoB3
Co3(BO3)2
Figure 3 The XRD patterns of Co-B catalysts
shows that the synthesized Co-B catalysts were highly crys-talline The characteristic peaks of phases were indexed inXRD patterns It was clear that sonochemical treatment doesnot affect the crystalline phases of Co-B catalysts
Figure 4 shows FT-IR spectrums of Co-B catalysts In adirect comparison of the observed FT-IR spectrums of bothcatalysts it was clearly seen that B-O band frequencies weredetected at the same wave number regions The bands at3197 cmminus1 and 3206 cmminus1 corresponded to vibration of H-O groups The bands at 1403 cmminus1 and 1350ndash935 cmminus1 werecontributed asymmetric stretching of B-O The bands were
Journal of Chemistry 5
0
20
40
60
80
100
120
650 1150 1650 2150 2650 3150 3650Wavenumber
CoB-2CoB-1
T(
)
(cmminus1)
Figure 4 The FT-IR spectrum of Co-B catalysts
0
20
40
60
80
0 5 10 15
Gen
erat
ed H
2vo
lum
e (m
L)
Time (min)
Alkaline sonohydrolysis
40∘C
60∘C
80∘C
NaBH4
(a)
Gen
erat
ed H
2vo
lum
e (m
L)
0
20
40
60
80
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysis
22∘C
40∘C
60∘C
NaBH4
(b)
Figure 5 Hydrogen generation volume versus time for sonohydrolysis and magnetic stirring hydrolysis of alkaline (10wt) 012 NaBH4
solutions in presence of 05mg CoB-1 catalyst
assigned between 950ndash870 cmminus1 and 710ndash795 cmminus1 and weresymmetric stretching band of B-O [28ndash30]
CoB-1 catalysts prepared via sonochemical coprecipita-tion synthesis show the best intrinsic and extrinsic propertiesthat are contributing factors to the catalytic activity Itwas concluded to start sonohydrolysis of alkaline NaBH
4
solutions with CoB-1 catalysts which were prepared viasonochemical coprecipitation synthesis
32 Sonochemical Approach to Hydrolysis of Alkaline NaBH4
Solutions In order to investigate the effect of sonochemicalapproach hydrolysis of alkaline NaBH
4solutions in presence
of CoB-1 catalyst were carried out with two different pro-cedures The evaluated H
2volume versus time during the
reactions was given in Figure 5 The H2generation started
immediately after catalyst contact with alkaline NaBH4solu-
tion As a result of this CoB-1 catalyst did not have inductionperiod to be active Effect of increasing in temperature wasshown in Figure 5TheH
2evolution shows direct proportion
with temperature in both systems In sonochemical alkalineNaBH
4solution hydrolysis hydrolysis time dropped 140min
from 941min by increasing of temperature from 22∘C to60∘C The same tendency was observed in magnetic stirringhydrolysis and reaction time decreased to 1388min
Figure 6 shows the effects of temperature and sono-waves on hydrogen generation It was clearly seen that bycomparing two different approach sono-waves developed thehydrolysis characteristics of system via cavitation on surfaceof catalystThe ultrasonic approach improved the interactionbetween the Co-B catalyst and alkaline NaBH
4solution
and made homogeneous distribution in the alkaline NaBH4
6 Journal of Chemistry
0
2000
4000
6000
8000
10000
40 60 80
Alkaline hydrolysis
SonohydrolysisMagnetic stirring hydrolysis
Temperature (∘C)
H2
gene
ratio
n ra
te (H
2ca
t)minus1
minus1
mL
min
gNaBH4
Figure 6Hydrogen generation rate comparison versus temperaturefor sonohydrolysis and magnetic stirring hydrolysis of alkaline(10wt) 012 NaBH
4solutions in presence of 05mg CoB-1 catalyst
solution and CoB-1 catalyst During the sonohydrolysiscavitation bubbles created high energy effects and this causedcontinuous acceleration of hydrogen generation rate [19]As can be seen ultrasonic treatment during the hydrolysisresults in maximum increase in the hydrogen generationfrom alkaline NaBH
4solution up to 65 at 40∘CThe authors
suggest to use of sonohydrolysis instead of magnetic stirringhydrolysis for improving the hydrogen generation rate ofsystem
Figure 7 shows the kinetic investigation of sonochemi-cal and magnetic stirring hydrolysis in presence of CoB-1catalyst The characterization of hydrolysis reaction behaviorwas identified by zero-order first-order and second-orderreaction kinetic models and Arrhenius theory As seen fromFigure 7 in both hydrolysis conditions the hydrolyses ofalkaline NaBH
4solutions were in compliance with zero-
order reaction kineticmodel and this indicated that hydrogengeneration rate was independent from concentration ofNaBH
4 Depending onArrhenius theory activation energy of
sonohydrolysis of alkalineNaBH4solutionwas 4615 kJsdotmolminus1
and its Arrhenius rate constant was 1989minminus1 For hydrol-ysis of alkaline NaBH
4solution which was carried out in
magnetic stirring systems the kinetic valueswere determinedas 5168 kJsdotmolminus1 activation energy and 1516minminus1 Arrheniusrate constant
In literature Co containing catalysts activation ener-gies were determined and summarized in Table 3 Theactivation energies of Co containing catalysts show vari-ety for example Copowder (7500 kJsdotmolminus1) Co-Raneyform (5370 kJsdotmolminus1) and active carbon supported Co-B(5780 kJsdotmolminus1) were relatively higher than our results whileCo nanoparticle (3500 kJsdotmolminus1) was lowerThe hydrolysis ofalkaline NaBH
4solution was carried out with sonochemical
approach the reaction kinetic was improved and value ofthem was decreased up to 12
Table 3 Activation energies in presence of various Co-basedcatalysts
Catalyst Activation energy(kJsdotmolminus1) References
Co powder 7500 [31]
Co nanoparticle 3500 [13]
Co (120572-Al2O3 support) 3263 [32]
Co (Raney form) 5370 [33]
Co-B (active carbon support) 5780 [34]
Co-B powder 6487 [12]
Co-B (clay support) 5632 [35]
Co-B 5273 [36]
CoB-1 (sonohydrolysis) 4615 At thiswork
CoB-1 (magnetic stirringhydrolysis) 5168 At this
work
4 Conclusion
In the present study sonochemical approach to coprecipi-tation synthesis of Co-B catalyst and hydrolysis of alkalineNaBH
4solutions was introducedThe following points result
from this studyThe sono-co-precipitation of CoCl
2sdot6H2O and B
2O3in
aqueous solution at pH 6 was proven to be a promisingprocedure in order to obtain Co-B crystalline catalyst withuniform 125 120583m particle size improved surface area andtexture properties On the other hand it was found that sono-chemical approach did not affect the crystalline structure andspectral properties of Co-B catalyst yet
The improving effect of sonochemical process on hydrol-ysis of alkaline NaBH
4solutions was approved when it
was compared with magnetic stirring system kinetic resultsHydrogen generation rate of alkaline NaBH
4solutions via
sonohydrolysis method in presence of CoB-1 catalyst hasshown enhanced influence at all temperatures Activationenergy as 4615 kJsdotmolminus1 of sonochemical coprecipitationsynthesized Co-B catalyst has compatible value comparedwith literature (32ndash75 kJsdotmolminus1) Rate law was formulized asgiven below
119903NaBH4
= 1989 sdot 119890minus4615RT (9)
As a result of this study the ultrasonicwaves improved theintrinsic and extrinsic properties of Co-B catalyst propertiesas specific surface area increased up to 70 particle sizedecreased up to 58 and hydrogen generation rate increasedup to 64 As can be seen sonochemical coprecipitationand sonohydrolysis proved to be promising techniques forsynthesis of Co-B catalyst and hydrolysis
Journal of Chemistry 7
000
002
004
006
008
010
012
014
0 5 10 15 20Time (min)
Alkaline sonohydrolysis Zero-order reaction kinetic
000
100
200
300
400
500
0 5 10 15 20Time (min)
Alkaline sonohydrolysis First-order reaction kinetic
000
10000
20000
30000
40000
50000
60000
0 5 10 15 20Time (min)
Alkaline sonohydrolysis Second-order reaction kinetic
000
002
004
006
008
010
012
014
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisZero-order reaction kinetic
000
100
200
300
400
500
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisFirst-order reaction kinetic
000
10000
20000
30000
40000
50000
60000
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisSecond-order reaction kinetic
Ln(C
CN
aBH
4)C
minusC
NaB
H4
(M)
Cminus
CN
aBH
4(M
)(1
CN
aBH
4)minus
(1C
)
22∘C
40∘C
60∘C
22∘C
40∘C
60∘C
NaBH4 NaBH4
NaBH4NaBH4
NaBH4 NaBH4
Ln(C
CN
aBH
4)
(1C
NaB
H4)minus
(1C
)
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
Figure 7The kinetic investigation the zero first and second reaction kinetic models for sonohydrolysis and magnetic stirring hydrolysis ofalkaline (10wt) 012M NaBH
4solutions
Symbols Used
119903 [H2molsdotminminus1sdotgminus1 cat] H
2generation rate
119864119886 [kJsdotmolminus1] Activation energy119877 [kJsdotmolminus1 sdot∘Cminus1] Gas constant119879 [∘C] Temperature
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
The authors would like to thank the Yildiz Technical Univer-sity Research Foundation (Project no 2012-07-01-YL02) forits financial support
References[1] S C Amendola S L Sharp-Goldman M S Janjua et al ldquoSafe
portable hydrogen gas generator using aqueous borohydridesolution and Ru catalystrdquo International Journal of HydrogenEnergy vol 25 no 10 pp 969ndash975 2000
8 Journal of Chemistry
[2] R Retnamma A Q Novais and C M Rangel ldquoKinetics ofhydrolysis of sodium borohydride for hydrogen productionin fuel cell applications a reviewrdquo International Journal ofHydrogen Energy vol 36 no 16 pp 9772ndash9790 2011
[3] O Akdim U B Demirci D Muller and P Miele ldquoCobalt(II) salts performing materials for generating hydrogen fromsodiumborohydriderdquo International Journal of Hydrogen Energyvol 34 no 6 pp 2631ndash2637 2009
[4] J Liang Y Li Y Huang et al ldquoSodium borohydride hydrolysison highly efficient Co-BPd catalystsrdquo International Journal ofHydrogen Energy vol 33 no 15 pp 4048ndash4054 2008
[5] U B Demirci O Akdim J Andrieux J Hannauer RChamoun and P Miele ldquoSodium borohydride hydrolysis ashydrogen generator Issues state of the art and applicabilityupstream froma fuel cellrdquo Fuel Cells vol 10 no 3 pp 335ndash3502010
[6] US Department of Energy Hydrogen Program 2007httpwwwhydrogenenergygov
[7] U B Demirci and P Miele ldquoSodium borohydride versusammonia borane in hydrogen storage and direct fuel cellapplicationsrdquo Energy and Environmental Science vol 2 no 6pp 627ndash637 2009
[8] B H Liu and Z P Li ldquoA review Hydrogen generation fromborohydride hydrolysis reactionrdquo Journal of Power Sources vol187 no 2 pp 527ndash534 2009
[9] S Cavaliere J Hannauer U B Demirci O Akdim and PMieleldquoEx situ characterization of N
2H4- NaBH
4- and NH
3BH3-
reduced cobalt catalysts used in NaBH4hydrolysisrdquo Catalysis
Today vol 170 no 1 pp 3ndash12 2011[10] H I Schlesinger E R Brown A E Finholitam J R Gilbreathh
H R Hoekstra and E A Hyde ldquoProcedures for the preparationof methyl boraterdquo Journal of American Chemical Society vol 75no 1 pp 213ndash215 1953
[11] A M Ozerova V I Simagina O V Komova et al ldquoCobaltborate catalysts for hydrogen production via hydrolysis ofsodium borohydriderdquo Journal of Alloys and Compounds vol513 pp 266ndash272 2012
[12] S U Jeong R K Kim E A Cho et al ldquoA study on hydrogengeneration from NaBH
4solution using the high-performance
Co-B catalystrdquo Journal of Power Sources vol 144 no 1 pp 129ndash134 2005
[13] R Khan S W Kim T-J Kim and C-M Nam ldquoComparativestudy of the photocatalytic performance of boron-iron Co-doped and boron-doped TiO
2nanoparticlesrdquoMaterials Chem-
istry and Physics vol 112 no 1 pp 167ndash172 2008[14] A Kanturk Figen and B Coskuner ldquoA novel perspective for
hydrogen generation from ammonia borane (NH3BH3) with
Co-B catalysts lsquoultrasonic Hydrolysisrsquordquo International Journal ofHydrogen Energy vol 38 no 6 pp 2824ndash2835 2013
[15] C C Yang M S Chen and Y W Chen ldquoHydrogen generationby hydrolysis of sodium borohydride on CoBSiO
2catalystrdquo
International Journal ofHydrogenEnergy vol 36 no 2 pp 1418ndash1423 2011
[16] R Patil P Bhoir P Deshpande T Wattamwar M Shirude andP Chaskar ldquoRelevance of sonochemistry or ultrasound (US)as a proficient means for the synthesis of fused heterocyclesrdquoUltrasonics Sonochemistry vol 20 no 6 pp 1327ndash1336 2013
[17] T Q Liu O Sakurai N Mizutani and M Kato ldquoPreparationof spherical fine ZnO particles by the spray pyrolysis methodusing ultrasonic atomization techniquesrdquo Journal of MaterialsScience vol 21 no 10 pp 3698ndash3702 1986
[18] S L Che K Takada K Takashima O Sakurai K Shinozakiand N Mizutani ldquoPreparation of dense spherical Ni particlesand hollow NiO particles by spray pyrolysisrdquo Journal of Materi-als Science vol 34 no 6 pp 1313ndash1318 1999
[19] C L Bianchi E Gotti L Toscano and V Ragaini ldquoPreparationof PdC catalysts via ultrasound a study of the metal distribu-tionrdquo Ultrasonics Sonochemistry vol 4 no 4 pp 317ndash320 1997
[20] S S Ostapenko L Jastrzebski J Lagowski and B SoporildquoIncreasing short minority carrier diffusion lengths in solar-grade polycrystalline silicon by ultrasound treatmentrdquo AppliedPhysics Letters vol 65 no 12 pp 1555ndash1557 1994
[21] M Run SWu andGWu ldquoUltrasonic synthesis ofmesoporousmolecular sieverdquo Microporous and Mesoporous Materials vol74 no 1-3 pp 37ndash47 2004
[22] U R Pillai E Sahle-Demessie and R S Varma ldquoAlterna-tive routes for catalyst preparation use of ultrasound andmicrowave irradiation for the preparation of vanadium phos-phorus oxide catalyst and their activity for hydrocarbon oxida-tionrdquo Applied Catalysis A General vol 252 no 1 pp 1ndash8 2003
[23] H LiH Li J ZhangWDai andMQiao ldquoUltrasound-assistedpreparation of a highly active and selective Co-B amorphousalloy catalyst in uniform spherical nanoparticlesrdquo Journal ofCatalysis vol 246 no 2 pp 301ndash307 2007
[24] M G Sulman ldquoEffects of ultrasound on catalytic processesrdquoRussian Chemical Reviews vol 69 no 2 pp 165ndash177 2000
[25] H Li J Zhang and H Li ldquoUltrasound-assisted preparationof a novel Ni-B amorphous catalyst in uniform nanoparticlesfor p-chloronitrobenzene hydrogenationrdquo Catalysis Communi-cations vol 8 no 12 pp 2212ndash2216 2007
[26] A J Hung S F Tsai Y Y Hsu J R Ku Y H Chen and CC Yu ldquoKinetics of sodium borohydride hydrolysis reaction forhydrogen generationrdquo International Journal ofHydrogen Energyvol 33 no 21 pp 6205ndash6215 2008
[27] O Levenspiel Chemical Reaction Engineering John Wiley ampSons New York NY USA 3rd edition 1999
[28] L Jun X Shuping and G Shiyang ldquoFT-IR and Ramanspectroscopic study of hydrated boratesrdquo Spectrochimica ActaA Molecular Spectroscopy vol 51 no 4 pp 519ndash532 1995
[29] A Kanturk M Sari and S Piskin ldquoSynthesis crystal structureand dehydration kinetics of NaB(OH)
4sdot2H2Ordquo Korean Journal
of Chemical Engineering vol 25 no 6 pp 1331ndash1337 2008[30] Q Zhang Y Wu X Sun and J Ortega ldquoKinetics of catalytic
hydrolysis of stabilized sodium borohydride solutionsrdquo Indus-trial and Engineering Chemistry Research vol 46 no 4 pp1120ndash1124 2007
[31] J Andrieux D Swierczynski L Laversenne et al ldquoAmultifactorstudy of catalyzed hydrolysis of solidNaBH
4on cobalt nanopar-
ticles thermodynamics and kineticsrdquo International Journal ofHydrogen Energy vol 34 no 2 pp 938ndash951 2009
[32] B H Liu Z P Li and S Suda ldquoNickel- and cobalt-basedcatalysts for hydrogen generation by hydrolysis of borohydriderdquoJournal of Alloys and Compounds vol 415 no 1-2 pp 288ndash2932006
[33] W Ye H Zhang D Xu L Ma and B Yi ldquoHydrogen generationutilizing alkaline sodium borohydride solution and supportedcobalt catalystrdquo Journal of Power Sources vol 164 no 2 pp 544ndash548 2007
[34] J Zhao H Ma and J Chen ldquoImproved hydrogen generationfrom alkaline image solution using carbon-supported image ascatalystsrdquo International Journal of Hydrogen Energy vol 32 no18 pp 4711ndash4716 2007
Journal of Chemistry 9
[35] H Tian Q Guo and D Xu ldquoHydrogen generation fromcatalytic hydrolysis of alkaline sodium borohydride solutionusing attapulgite clay-supported Co-B catalystrdquo Journal ofPower Sources vol 195 no 8 pp 2136ndash2142 2010
[36] C H Liu B H Chen C L Hsueh J R Ku M S Jeng and FTsau ldquoHydrogen generation from hydrolysis of sodium boro-hydride using Ni-Ru nanocomposite as catalystsrdquo InternationalJournal of Hydrogen Energy vol 34 no 5 pp 2153ndash2163 2009
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Journal of Chemistry 5
0
20
40
60
80
100
120
650 1150 1650 2150 2650 3150 3650Wavenumber
CoB-2CoB-1
T(
)
(cmminus1)
Figure 4 The FT-IR spectrum of Co-B catalysts
0
20
40
60
80
0 5 10 15
Gen
erat
ed H
2vo
lum
e (m
L)
Time (min)
Alkaline sonohydrolysis
40∘C
60∘C
80∘C
NaBH4
(a)
Gen
erat
ed H
2vo
lum
e (m
L)
0
20
40
60
80
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysis
22∘C
40∘C
60∘C
NaBH4
(b)
Figure 5 Hydrogen generation volume versus time for sonohydrolysis and magnetic stirring hydrolysis of alkaline (10wt) 012 NaBH4
solutions in presence of 05mg CoB-1 catalyst
assigned between 950ndash870 cmminus1 and 710ndash795 cmminus1 and weresymmetric stretching band of B-O [28ndash30]
CoB-1 catalysts prepared via sonochemical coprecipita-tion synthesis show the best intrinsic and extrinsic propertiesthat are contributing factors to the catalytic activity Itwas concluded to start sonohydrolysis of alkaline NaBH
4
solutions with CoB-1 catalysts which were prepared viasonochemical coprecipitation synthesis
32 Sonochemical Approach to Hydrolysis of Alkaline NaBH4
Solutions In order to investigate the effect of sonochemicalapproach hydrolysis of alkaline NaBH
4solutions in presence
of CoB-1 catalyst were carried out with two different pro-cedures The evaluated H
2volume versus time during the
reactions was given in Figure 5 The H2generation started
immediately after catalyst contact with alkaline NaBH4solu-
tion As a result of this CoB-1 catalyst did not have inductionperiod to be active Effect of increasing in temperature wasshown in Figure 5TheH
2evolution shows direct proportion
with temperature in both systems In sonochemical alkalineNaBH
4solution hydrolysis hydrolysis time dropped 140min
from 941min by increasing of temperature from 22∘C to60∘C The same tendency was observed in magnetic stirringhydrolysis and reaction time decreased to 1388min
Figure 6 shows the effects of temperature and sono-waves on hydrogen generation It was clearly seen that bycomparing two different approach sono-waves developed thehydrolysis characteristics of system via cavitation on surfaceof catalystThe ultrasonic approach improved the interactionbetween the Co-B catalyst and alkaline NaBH
4solution
and made homogeneous distribution in the alkaline NaBH4
6 Journal of Chemistry
0
2000
4000
6000
8000
10000
40 60 80
Alkaline hydrolysis
SonohydrolysisMagnetic stirring hydrolysis
Temperature (∘C)
H2
gene
ratio
n ra
te (H
2ca
t)minus1
minus1
mL
min
gNaBH4
Figure 6Hydrogen generation rate comparison versus temperaturefor sonohydrolysis and magnetic stirring hydrolysis of alkaline(10wt) 012 NaBH
4solutions in presence of 05mg CoB-1 catalyst
solution and CoB-1 catalyst During the sonohydrolysiscavitation bubbles created high energy effects and this causedcontinuous acceleration of hydrogen generation rate [19]As can be seen ultrasonic treatment during the hydrolysisresults in maximum increase in the hydrogen generationfrom alkaline NaBH
4solution up to 65 at 40∘CThe authors
suggest to use of sonohydrolysis instead of magnetic stirringhydrolysis for improving the hydrogen generation rate ofsystem
Figure 7 shows the kinetic investigation of sonochemi-cal and magnetic stirring hydrolysis in presence of CoB-1catalyst The characterization of hydrolysis reaction behaviorwas identified by zero-order first-order and second-orderreaction kinetic models and Arrhenius theory As seen fromFigure 7 in both hydrolysis conditions the hydrolyses ofalkaline NaBH
4solutions were in compliance with zero-
order reaction kineticmodel and this indicated that hydrogengeneration rate was independent from concentration ofNaBH
4 Depending onArrhenius theory activation energy of
sonohydrolysis of alkalineNaBH4solutionwas 4615 kJsdotmolminus1
and its Arrhenius rate constant was 1989minminus1 For hydrol-ysis of alkaline NaBH
4solution which was carried out in
magnetic stirring systems the kinetic valueswere determinedas 5168 kJsdotmolminus1 activation energy and 1516minminus1 Arrheniusrate constant
In literature Co containing catalysts activation ener-gies were determined and summarized in Table 3 Theactivation energies of Co containing catalysts show vari-ety for example Copowder (7500 kJsdotmolminus1) Co-Raneyform (5370 kJsdotmolminus1) and active carbon supported Co-B(5780 kJsdotmolminus1) were relatively higher than our results whileCo nanoparticle (3500 kJsdotmolminus1) was lowerThe hydrolysis ofalkaline NaBH
4solution was carried out with sonochemical
approach the reaction kinetic was improved and value ofthem was decreased up to 12
Table 3 Activation energies in presence of various Co-basedcatalysts
Catalyst Activation energy(kJsdotmolminus1) References
Co powder 7500 [31]
Co nanoparticle 3500 [13]
Co (120572-Al2O3 support) 3263 [32]
Co (Raney form) 5370 [33]
Co-B (active carbon support) 5780 [34]
Co-B powder 6487 [12]
Co-B (clay support) 5632 [35]
Co-B 5273 [36]
CoB-1 (sonohydrolysis) 4615 At thiswork
CoB-1 (magnetic stirringhydrolysis) 5168 At this
work
4 Conclusion
In the present study sonochemical approach to coprecipi-tation synthesis of Co-B catalyst and hydrolysis of alkalineNaBH
4solutions was introducedThe following points result
from this studyThe sono-co-precipitation of CoCl
2sdot6H2O and B
2O3in
aqueous solution at pH 6 was proven to be a promisingprocedure in order to obtain Co-B crystalline catalyst withuniform 125 120583m particle size improved surface area andtexture properties On the other hand it was found that sono-chemical approach did not affect the crystalline structure andspectral properties of Co-B catalyst yet
The improving effect of sonochemical process on hydrol-ysis of alkaline NaBH
4solutions was approved when it
was compared with magnetic stirring system kinetic resultsHydrogen generation rate of alkaline NaBH
4solutions via
sonohydrolysis method in presence of CoB-1 catalyst hasshown enhanced influence at all temperatures Activationenergy as 4615 kJsdotmolminus1 of sonochemical coprecipitationsynthesized Co-B catalyst has compatible value comparedwith literature (32ndash75 kJsdotmolminus1) Rate law was formulized asgiven below
119903NaBH4
= 1989 sdot 119890minus4615RT (9)
As a result of this study the ultrasonicwaves improved theintrinsic and extrinsic properties of Co-B catalyst propertiesas specific surface area increased up to 70 particle sizedecreased up to 58 and hydrogen generation rate increasedup to 64 As can be seen sonochemical coprecipitationand sonohydrolysis proved to be promising techniques forsynthesis of Co-B catalyst and hydrolysis
Journal of Chemistry 7
000
002
004
006
008
010
012
014
0 5 10 15 20Time (min)
Alkaline sonohydrolysis Zero-order reaction kinetic
000
100
200
300
400
500
0 5 10 15 20Time (min)
Alkaline sonohydrolysis First-order reaction kinetic
000
10000
20000
30000
40000
50000
60000
0 5 10 15 20Time (min)
Alkaline sonohydrolysis Second-order reaction kinetic
000
002
004
006
008
010
012
014
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisZero-order reaction kinetic
000
100
200
300
400
500
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisFirst-order reaction kinetic
000
10000
20000
30000
40000
50000
60000
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisSecond-order reaction kinetic
Ln(C
CN
aBH
4)C
minusC
NaB
H4
(M)
Cminus
CN
aBH
4(M
)(1
CN
aBH
4)minus
(1C
)
22∘C
40∘C
60∘C
22∘C
40∘C
60∘C
NaBH4 NaBH4
NaBH4NaBH4
NaBH4 NaBH4
Ln(C
CN
aBH
4)
(1C
NaB
H4)minus
(1C
)
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
Figure 7The kinetic investigation the zero first and second reaction kinetic models for sonohydrolysis and magnetic stirring hydrolysis ofalkaline (10wt) 012M NaBH
4solutions
Symbols Used
119903 [H2molsdotminminus1sdotgminus1 cat] H
2generation rate
119864119886 [kJsdotmolminus1] Activation energy119877 [kJsdotmolminus1 sdot∘Cminus1] Gas constant119879 [∘C] Temperature
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
The authors would like to thank the Yildiz Technical Univer-sity Research Foundation (Project no 2012-07-01-YL02) forits financial support
References[1] S C Amendola S L Sharp-Goldman M S Janjua et al ldquoSafe
portable hydrogen gas generator using aqueous borohydridesolution and Ru catalystrdquo International Journal of HydrogenEnergy vol 25 no 10 pp 969ndash975 2000
8 Journal of Chemistry
[2] R Retnamma A Q Novais and C M Rangel ldquoKinetics ofhydrolysis of sodium borohydride for hydrogen productionin fuel cell applications a reviewrdquo International Journal ofHydrogen Energy vol 36 no 16 pp 9772ndash9790 2011
[3] O Akdim U B Demirci D Muller and P Miele ldquoCobalt(II) salts performing materials for generating hydrogen fromsodiumborohydriderdquo International Journal of Hydrogen Energyvol 34 no 6 pp 2631ndash2637 2009
[4] J Liang Y Li Y Huang et al ldquoSodium borohydride hydrolysison highly efficient Co-BPd catalystsrdquo International Journal ofHydrogen Energy vol 33 no 15 pp 4048ndash4054 2008
[5] U B Demirci O Akdim J Andrieux J Hannauer RChamoun and P Miele ldquoSodium borohydride hydrolysis ashydrogen generator Issues state of the art and applicabilityupstream froma fuel cellrdquo Fuel Cells vol 10 no 3 pp 335ndash3502010
[6] US Department of Energy Hydrogen Program 2007httpwwwhydrogenenergygov
[7] U B Demirci and P Miele ldquoSodium borohydride versusammonia borane in hydrogen storage and direct fuel cellapplicationsrdquo Energy and Environmental Science vol 2 no 6pp 627ndash637 2009
[8] B H Liu and Z P Li ldquoA review Hydrogen generation fromborohydride hydrolysis reactionrdquo Journal of Power Sources vol187 no 2 pp 527ndash534 2009
[9] S Cavaliere J Hannauer U B Demirci O Akdim and PMieleldquoEx situ characterization of N
2H4- NaBH
4- and NH
3BH3-
reduced cobalt catalysts used in NaBH4hydrolysisrdquo Catalysis
Today vol 170 no 1 pp 3ndash12 2011[10] H I Schlesinger E R Brown A E Finholitam J R Gilbreathh
H R Hoekstra and E A Hyde ldquoProcedures for the preparationof methyl boraterdquo Journal of American Chemical Society vol 75no 1 pp 213ndash215 1953
[11] A M Ozerova V I Simagina O V Komova et al ldquoCobaltborate catalysts for hydrogen production via hydrolysis ofsodium borohydriderdquo Journal of Alloys and Compounds vol513 pp 266ndash272 2012
[12] S U Jeong R K Kim E A Cho et al ldquoA study on hydrogengeneration from NaBH
4solution using the high-performance
Co-B catalystrdquo Journal of Power Sources vol 144 no 1 pp 129ndash134 2005
[13] R Khan S W Kim T-J Kim and C-M Nam ldquoComparativestudy of the photocatalytic performance of boron-iron Co-doped and boron-doped TiO
2nanoparticlesrdquoMaterials Chem-
istry and Physics vol 112 no 1 pp 167ndash172 2008[14] A Kanturk Figen and B Coskuner ldquoA novel perspective for
hydrogen generation from ammonia borane (NH3BH3) with
Co-B catalysts lsquoultrasonic Hydrolysisrsquordquo International Journal ofHydrogen Energy vol 38 no 6 pp 2824ndash2835 2013
[15] C C Yang M S Chen and Y W Chen ldquoHydrogen generationby hydrolysis of sodium borohydride on CoBSiO
2catalystrdquo
International Journal ofHydrogenEnergy vol 36 no 2 pp 1418ndash1423 2011
[16] R Patil P Bhoir P Deshpande T Wattamwar M Shirude andP Chaskar ldquoRelevance of sonochemistry or ultrasound (US)as a proficient means for the synthesis of fused heterocyclesrdquoUltrasonics Sonochemistry vol 20 no 6 pp 1327ndash1336 2013
[17] T Q Liu O Sakurai N Mizutani and M Kato ldquoPreparationof spherical fine ZnO particles by the spray pyrolysis methodusing ultrasonic atomization techniquesrdquo Journal of MaterialsScience vol 21 no 10 pp 3698ndash3702 1986
[18] S L Che K Takada K Takashima O Sakurai K Shinozakiand N Mizutani ldquoPreparation of dense spherical Ni particlesand hollow NiO particles by spray pyrolysisrdquo Journal of Materi-als Science vol 34 no 6 pp 1313ndash1318 1999
[19] C L Bianchi E Gotti L Toscano and V Ragaini ldquoPreparationof PdC catalysts via ultrasound a study of the metal distribu-tionrdquo Ultrasonics Sonochemistry vol 4 no 4 pp 317ndash320 1997
[20] S S Ostapenko L Jastrzebski J Lagowski and B SoporildquoIncreasing short minority carrier diffusion lengths in solar-grade polycrystalline silicon by ultrasound treatmentrdquo AppliedPhysics Letters vol 65 no 12 pp 1555ndash1557 1994
[21] M Run SWu andGWu ldquoUltrasonic synthesis ofmesoporousmolecular sieverdquo Microporous and Mesoporous Materials vol74 no 1-3 pp 37ndash47 2004
[22] U R Pillai E Sahle-Demessie and R S Varma ldquoAlterna-tive routes for catalyst preparation use of ultrasound andmicrowave irradiation for the preparation of vanadium phos-phorus oxide catalyst and their activity for hydrocarbon oxida-tionrdquo Applied Catalysis A General vol 252 no 1 pp 1ndash8 2003
[23] H LiH Li J ZhangWDai andMQiao ldquoUltrasound-assistedpreparation of a highly active and selective Co-B amorphousalloy catalyst in uniform spherical nanoparticlesrdquo Journal ofCatalysis vol 246 no 2 pp 301ndash307 2007
[24] M G Sulman ldquoEffects of ultrasound on catalytic processesrdquoRussian Chemical Reviews vol 69 no 2 pp 165ndash177 2000
[25] H Li J Zhang and H Li ldquoUltrasound-assisted preparationof a novel Ni-B amorphous catalyst in uniform nanoparticlesfor p-chloronitrobenzene hydrogenationrdquo Catalysis Communi-cations vol 8 no 12 pp 2212ndash2216 2007
[26] A J Hung S F Tsai Y Y Hsu J R Ku Y H Chen and CC Yu ldquoKinetics of sodium borohydride hydrolysis reaction forhydrogen generationrdquo International Journal ofHydrogen Energyvol 33 no 21 pp 6205ndash6215 2008
[27] O Levenspiel Chemical Reaction Engineering John Wiley ampSons New York NY USA 3rd edition 1999
[28] L Jun X Shuping and G Shiyang ldquoFT-IR and Ramanspectroscopic study of hydrated boratesrdquo Spectrochimica ActaA Molecular Spectroscopy vol 51 no 4 pp 519ndash532 1995
[29] A Kanturk M Sari and S Piskin ldquoSynthesis crystal structureand dehydration kinetics of NaB(OH)
4sdot2H2Ordquo Korean Journal
of Chemical Engineering vol 25 no 6 pp 1331ndash1337 2008[30] Q Zhang Y Wu X Sun and J Ortega ldquoKinetics of catalytic
hydrolysis of stabilized sodium borohydride solutionsrdquo Indus-trial and Engineering Chemistry Research vol 46 no 4 pp1120ndash1124 2007
[31] J Andrieux D Swierczynski L Laversenne et al ldquoAmultifactorstudy of catalyzed hydrolysis of solidNaBH
4on cobalt nanopar-
ticles thermodynamics and kineticsrdquo International Journal ofHydrogen Energy vol 34 no 2 pp 938ndash951 2009
[32] B H Liu Z P Li and S Suda ldquoNickel- and cobalt-basedcatalysts for hydrogen generation by hydrolysis of borohydriderdquoJournal of Alloys and Compounds vol 415 no 1-2 pp 288ndash2932006
[33] W Ye H Zhang D Xu L Ma and B Yi ldquoHydrogen generationutilizing alkaline sodium borohydride solution and supportedcobalt catalystrdquo Journal of Power Sources vol 164 no 2 pp 544ndash548 2007
[34] J Zhao H Ma and J Chen ldquoImproved hydrogen generationfrom alkaline image solution using carbon-supported image ascatalystsrdquo International Journal of Hydrogen Energy vol 32 no18 pp 4711ndash4716 2007
Journal of Chemistry 9
[35] H Tian Q Guo and D Xu ldquoHydrogen generation fromcatalytic hydrolysis of alkaline sodium borohydride solutionusing attapulgite clay-supported Co-B catalystrdquo Journal ofPower Sources vol 195 no 8 pp 2136ndash2142 2010
[36] C H Liu B H Chen C L Hsueh J R Ku M S Jeng and FTsau ldquoHydrogen generation from hydrolysis of sodium boro-hydride using Ni-Ru nanocomposite as catalystsrdquo InternationalJournal of Hydrogen Energy vol 34 no 5 pp 2153ndash2163 2009
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
6 Journal of Chemistry
0
2000
4000
6000
8000
10000
40 60 80
Alkaline hydrolysis
SonohydrolysisMagnetic stirring hydrolysis
Temperature (∘C)
H2
gene
ratio
n ra
te (H
2ca
t)minus1
minus1
mL
min
gNaBH4
Figure 6Hydrogen generation rate comparison versus temperaturefor sonohydrolysis and magnetic stirring hydrolysis of alkaline(10wt) 012 NaBH
4solutions in presence of 05mg CoB-1 catalyst
solution and CoB-1 catalyst During the sonohydrolysiscavitation bubbles created high energy effects and this causedcontinuous acceleration of hydrogen generation rate [19]As can be seen ultrasonic treatment during the hydrolysisresults in maximum increase in the hydrogen generationfrom alkaline NaBH
4solution up to 65 at 40∘CThe authors
suggest to use of sonohydrolysis instead of magnetic stirringhydrolysis for improving the hydrogen generation rate ofsystem
Figure 7 shows the kinetic investigation of sonochemi-cal and magnetic stirring hydrolysis in presence of CoB-1catalyst The characterization of hydrolysis reaction behaviorwas identified by zero-order first-order and second-orderreaction kinetic models and Arrhenius theory As seen fromFigure 7 in both hydrolysis conditions the hydrolyses ofalkaline NaBH
4solutions were in compliance with zero-
order reaction kineticmodel and this indicated that hydrogengeneration rate was independent from concentration ofNaBH
4 Depending onArrhenius theory activation energy of
sonohydrolysis of alkalineNaBH4solutionwas 4615 kJsdotmolminus1
and its Arrhenius rate constant was 1989minminus1 For hydrol-ysis of alkaline NaBH
4solution which was carried out in
magnetic stirring systems the kinetic valueswere determinedas 5168 kJsdotmolminus1 activation energy and 1516minminus1 Arrheniusrate constant
In literature Co containing catalysts activation ener-gies were determined and summarized in Table 3 Theactivation energies of Co containing catalysts show vari-ety for example Copowder (7500 kJsdotmolminus1) Co-Raneyform (5370 kJsdotmolminus1) and active carbon supported Co-B(5780 kJsdotmolminus1) were relatively higher than our results whileCo nanoparticle (3500 kJsdotmolminus1) was lowerThe hydrolysis ofalkaline NaBH
4solution was carried out with sonochemical
approach the reaction kinetic was improved and value ofthem was decreased up to 12
Table 3 Activation energies in presence of various Co-basedcatalysts
Catalyst Activation energy(kJsdotmolminus1) References
Co powder 7500 [31]
Co nanoparticle 3500 [13]
Co (120572-Al2O3 support) 3263 [32]
Co (Raney form) 5370 [33]
Co-B (active carbon support) 5780 [34]
Co-B powder 6487 [12]
Co-B (clay support) 5632 [35]
Co-B 5273 [36]
CoB-1 (sonohydrolysis) 4615 At thiswork
CoB-1 (magnetic stirringhydrolysis) 5168 At this
work
4 Conclusion
In the present study sonochemical approach to coprecipi-tation synthesis of Co-B catalyst and hydrolysis of alkalineNaBH
4solutions was introducedThe following points result
from this studyThe sono-co-precipitation of CoCl
2sdot6H2O and B
2O3in
aqueous solution at pH 6 was proven to be a promisingprocedure in order to obtain Co-B crystalline catalyst withuniform 125 120583m particle size improved surface area andtexture properties On the other hand it was found that sono-chemical approach did not affect the crystalline structure andspectral properties of Co-B catalyst yet
The improving effect of sonochemical process on hydrol-ysis of alkaline NaBH
4solutions was approved when it
was compared with magnetic stirring system kinetic resultsHydrogen generation rate of alkaline NaBH
4solutions via
sonohydrolysis method in presence of CoB-1 catalyst hasshown enhanced influence at all temperatures Activationenergy as 4615 kJsdotmolminus1 of sonochemical coprecipitationsynthesized Co-B catalyst has compatible value comparedwith literature (32ndash75 kJsdotmolminus1) Rate law was formulized asgiven below
119903NaBH4
= 1989 sdot 119890minus4615RT (9)
As a result of this study the ultrasonicwaves improved theintrinsic and extrinsic properties of Co-B catalyst propertiesas specific surface area increased up to 70 particle sizedecreased up to 58 and hydrogen generation rate increasedup to 64 As can be seen sonochemical coprecipitationand sonohydrolysis proved to be promising techniques forsynthesis of Co-B catalyst and hydrolysis
Journal of Chemistry 7
000
002
004
006
008
010
012
014
0 5 10 15 20Time (min)
Alkaline sonohydrolysis Zero-order reaction kinetic
000
100
200
300
400
500
0 5 10 15 20Time (min)
Alkaline sonohydrolysis First-order reaction kinetic
000
10000
20000
30000
40000
50000
60000
0 5 10 15 20Time (min)
Alkaline sonohydrolysis Second-order reaction kinetic
000
002
004
006
008
010
012
014
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisZero-order reaction kinetic
000
100
200
300
400
500
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisFirst-order reaction kinetic
000
10000
20000
30000
40000
50000
60000
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisSecond-order reaction kinetic
Ln(C
CN
aBH
4)C
minusC
NaB
H4
(M)
Cminus
CN
aBH
4(M
)(1
CN
aBH
4)minus
(1C
)
22∘C
40∘C
60∘C
22∘C
40∘C
60∘C
NaBH4 NaBH4
NaBH4NaBH4
NaBH4 NaBH4
Ln(C
CN
aBH
4)
(1C
NaB
H4)minus
(1C
)
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
Figure 7The kinetic investigation the zero first and second reaction kinetic models for sonohydrolysis and magnetic stirring hydrolysis ofalkaline (10wt) 012M NaBH
4solutions
Symbols Used
119903 [H2molsdotminminus1sdotgminus1 cat] H
2generation rate
119864119886 [kJsdotmolminus1] Activation energy119877 [kJsdotmolminus1 sdot∘Cminus1] Gas constant119879 [∘C] Temperature
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
The authors would like to thank the Yildiz Technical Univer-sity Research Foundation (Project no 2012-07-01-YL02) forits financial support
References[1] S C Amendola S L Sharp-Goldman M S Janjua et al ldquoSafe
portable hydrogen gas generator using aqueous borohydridesolution and Ru catalystrdquo International Journal of HydrogenEnergy vol 25 no 10 pp 969ndash975 2000
8 Journal of Chemistry
[2] R Retnamma A Q Novais and C M Rangel ldquoKinetics ofhydrolysis of sodium borohydride for hydrogen productionin fuel cell applications a reviewrdquo International Journal ofHydrogen Energy vol 36 no 16 pp 9772ndash9790 2011
[3] O Akdim U B Demirci D Muller and P Miele ldquoCobalt(II) salts performing materials for generating hydrogen fromsodiumborohydriderdquo International Journal of Hydrogen Energyvol 34 no 6 pp 2631ndash2637 2009
[4] J Liang Y Li Y Huang et al ldquoSodium borohydride hydrolysison highly efficient Co-BPd catalystsrdquo International Journal ofHydrogen Energy vol 33 no 15 pp 4048ndash4054 2008
[5] U B Demirci O Akdim J Andrieux J Hannauer RChamoun and P Miele ldquoSodium borohydride hydrolysis ashydrogen generator Issues state of the art and applicabilityupstream froma fuel cellrdquo Fuel Cells vol 10 no 3 pp 335ndash3502010
[6] US Department of Energy Hydrogen Program 2007httpwwwhydrogenenergygov
[7] U B Demirci and P Miele ldquoSodium borohydride versusammonia borane in hydrogen storage and direct fuel cellapplicationsrdquo Energy and Environmental Science vol 2 no 6pp 627ndash637 2009
[8] B H Liu and Z P Li ldquoA review Hydrogen generation fromborohydride hydrolysis reactionrdquo Journal of Power Sources vol187 no 2 pp 527ndash534 2009
[9] S Cavaliere J Hannauer U B Demirci O Akdim and PMieleldquoEx situ characterization of N
2H4- NaBH
4- and NH
3BH3-
reduced cobalt catalysts used in NaBH4hydrolysisrdquo Catalysis
Today vol 170 no 1 pp 3ndash12 2011[10] H I Schlesinger E R Brown A E Finholitam J R Gilbreathh
H R Hoekstra and E A Hyde ldquoProcedures for the preparationof methyl boraterdquo Journal of American Chemical Society vol 75no 1 pp 213ndash215 1953
[11] A M Ozerova V I Simagina O V Komova et al ldquoCobaltborate catalysts for hydrogen production via hydrolysis ofsodium borohydriderdquo Journal of Alloys and Compounds vol513 pp 266ndash272 2012
[12] S U Jeong R K Kim E A Cho et al ldquoA study on hydrogengeneration from NaBH
4solution using the high-performance
Co-B catalystrdquo Journal of Power Sources vol 144 no 1 pp 129ndash134 2005
[13] R Khan S W Kim T-J Kim and C-M Nam ldquoComparativestudy of the photocatalytic performance of boron-iron Co-doped and boron-doped TiO
2nanoparticlesrdquoMaterials Chem-
istry and Physics vol 112 no 1 pp 167ndash172 2008[14] A Kanturk Figen and B Coskuner ldquoA novel perspective for
hydrogen generation from ammonia borane (NH3BH3) with
Co-B catalysts lsquoultrasonic Hydrolysisrsquordquo International Journal ofHydrogen Energy vol 38 no 6 pp 2824ndash2835 2013
[15] C C Yang M S Chen and Y W Chen ldquoHydrogen generationby hydrolysis of sodium borohydride on CoBSiO
2catalystrdquo
International Journal ofHydrogenEnergy vol 36 no 2 pp 1418ndash1423 2011
[16] R Patil P Bhoir P Deshpande T Wattamwar M Shirude andP Chaskar ldquoRelevance of sonochemistry or ultrasound (US)as a proficient means for the synthesis of fused heterocyclesrdquoUltrasonics Sonochemistry vol 20 no 6 pp 1327ndash1336 2013
[17] T Q Liu O Sakurai N Mizutani and M Kato ldquoPreparationof spherical fine ZnO particles by the spray pyrolysis methodusing ultrasonic atomization techniquesrdquo Journal of MaterialsScience vol 21 no 10 pp 3698ndash3702 1986
[18] S L Che K Takada K Takashima O Sakurai K Shinozakiand N Mizutani ldquoPreparation of dense spherical Ni particlesand hollow NiO particles by spray pyrolysisrdquo Journal of Materi-als Science vol 34 no 6 pp 1313ndash1318 1999
[19] C L Bianchi E Gotti L Toscano and V Ragaini ldquoPreparationof PdC catalysts via ultrasound a study of the metal distribu-tionrdquo Ultrasonics Sonochemistry vol 4 no 4 pp 317ndash320 1997
[20] S S Ostapenko L Jastrzebski J Lagowski and B SoporildquoIncreasing short minority carrier diffusion lengths in solar-grade polycrystalline silicon by ultrasound treatmentrdquo AppliedPhysics Letters vol 65 no 12 pp 1555ndash1557 1994
[21] M Run SWu andGWu ldquoUltrasonic synthesis ofmesoporousmolecular sieverdquo Microporous and Mesoporous Materials vol74 no 1-3 pp 37ndash47 2004
[22] U R Pillai E Sahle-Demessie and R S Varma ldquoAlterna-tive routes for catalyst preparation use of ultrasound andmicrowave irradiation for the preparation of vanadium phos-phorus oxide catalyst and their activity for hydrocarbon oxida-tionrdquo Applied Catalysis A General vol 252 no 1 pp 1ndash8 2003
[23] H LiH Li J ZhangWDai andMQiao ldquoUltrasound-assistedpreparation of a highly active and selective Co-B amorphousalloy catalyst in uniform spherical nanoparticlesrdquo Journal ofCatalysis vol 246 no 2 pp 301ndash307 2007
[24] M G Sulman ldquoEffects of ultrasound on catalytic processesrdquoRussian Chemical Reviews vol 69 no 2 pp 165ndash177 2000
[25] H Li J Zhang and H Li ldquoUltrasound-assisted preparationof a novel Ni-B amorphous catalyst in uniform nanoparticlesfor p-chloronitrobenzene hydrogenationrdquo Catalysis Communi-cations vol 8 no 12 pp 2212ndash2216 2007
[26] A J Hung S F Tsai Y Y Hsu J R Ku Y H Chen and CC Yu ldquoKinetics of sodium borohydride hydrolysis reaction forhydrogen generationrdquo International Journal ofHydrogen Energyvol 33 no 21 pp 6205ndash6215 2008
[27] O Levenspiel Chemical Reaction Engineering John Wiley ampSons New York NY USA 3rd edition 1999
[28] L Jun X Shuping and G Shiyang ldquoFT-IR and Ramanspectroscopic study of hydrated boratesrdquo Spectrochimica ActaA Molecular Spectroscopy vol 51 no 4 pp 519ndash532 1995
[29] A Kanturk M Sari and S Piskin ldquoSynthesis crystal structureand dehydration kinetics of NaB(OH)
4sdot2H2Ordquo Korean Journal
of Chemical Engineering vol 25 no 6 pp 1331ndash1337 2008[30] Q Zhang Y Wu X Sun and J Ortega ldquoKinetics of catalytic
hydrolysis of stabilized sodium borohydride solutionsrdquo Indus-trial and Engineering Chemistry Research vol 46 no 4 pp1120ndash1124 2007
[31] J Andrieux D Swierczynski L Laversenne et al ldquoAmultifactorstudy of catalyzed hydrolysis of solidNaBH
4on cobalt nanopar-
ticles thermodynamics and kineticsrdquo International Journal ofHydrogen Energy vol 34 no 2 pp 938ndash951 2009
[32] B H Liu Z P Li and S Suda ldquoNickel- and cobalt-basedcatalysts for hydrogen generation by hydrolysis of borohydriderdquoJournal of Alloys and Compounds vol 415 no 1-2 pp 288ndash2932006
[33] W Ye H Zhang D Xu L Ma and B Yi ldquoHydrogen generationutilizing alkaline sodium borohydride solution and supportedcobalt catalystrdquo Journal of Power Sources vol 164 no 2 pp 544ndash548 2007
[34] J Zhao H Ma and J Chen ldquoImproved hydrogen generationfrom alkaline image solution using carbon-supported image ascatalystsrdquo International Journal of Hydrogen Energy vol 32 no18 pp 4711ndash4716 2007
Journal of Chemistry 9
[35] H Tian Q Guo and D Xu ldquoHydrogen generation fromcatalytic hydrolysis of alkaline sodium borohydride solutionusing attapulgite clay-supported Co-B catalystrdquo Journal ofPower Sources vol 195 no 8 pp 2136ndash2142 2010
[36] C H Liu B H Chen C L Hsueh J R Ku M S Jeng and FTsau ldquoHydrogen generation from hydrolysis of sodium boro-hydride using Ni-Ru nanocomposite as catalystsrdquo InternationalJournal of Hydrogen Energy vol 34 no 5 pp 2153ndash2163 2009
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Journal of Chemistry 7
000
002
004
006
008
010
012
014
0 5 10 15 20Time (min)
Alkaline sonohydrolysis Zero-order reaction kinetic
000
100
200
300
400
500
0 5 10 15 20Time (min)
Alkaline sonohydrolysis First-order reaction kinetic
000
10000
20000
30000
40000
50000
60000
0 5 10 15 20Time (min)
Alkaline sonohydrolysis Second-order reaction kinetic
000
002
004
006
008
010
012
014
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisZero-order reaction kinetic
000
100
200
300
400
500
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisFirst-order reaction kinetic
000
10000
20000
30000
40000
50000
60000
0 5 10 15 20Time (min)
Alkaline magnetic stirring hydrolysisSecond-order reaction kinetic
Ln(C
CN
aBH
4)C
minusC
NaB
H4
(M)
Cminus
CN
aBH
4(M
)(1
CN
aBH
4)minus
(1C
)
22∘C
40∘C
60∘C
22∘C
40∘C
60∘C
NaBH4 NaBH4
NaBH4NaBH4
NaBH4 NaBH4
Ln(C
CN
aBH
4)
(1C
NaB
H4)minus
(1C
)
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
NaB
H4 0
Figure 7The kinetic investigation the zero first and second reaction kinetic models for sonohydrolysis and magnetic stirring hydrolysis ofalkaline (10wt) 012M NaBH
4solutions
Symbols Used
119903 [H2molsdotminminus1sdotgminus1 cat] H
2generation rate
119864119886 [kJsdotmolminus1] Activation energy119877 [kJsdotmolminus1 sdot∘Cminus1] Gas constant119879 [∘C] Temperature
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
The authors would like to thank the Yildiz Technical Univer-sity Research Foundation (Project no 2012-07-01-YL02) forits financial support
References[1] S C Amendola S L Sharp-Goldman M S Janjua et al ldquoSafe
portable hydrogen gas generator using aqueous borohydridesolution and Ru catalystrdquo International Journal of HydrogenEnergy vol 25 no 10 pp 969ndash975 2000
8 Journal of Chemistry
[2] R Retnamma A Q Novais and C M Rangel ldquoKinetics ofhydrolysis of sodium borohydride for hydrogen productionin fuel cell applications a reviewrdquo International Journal ofHydrogen Energy vol 36 no 16 pp 9772ndash9790 2011
[3] O Akdim U B Demirci D Muller and P Miele ldquoCobalt(II) salts performing materials for generating hydrogen fromsodiumborohydriderdquo International Journal of Hydrogen Energyvol 34 no 6 pp 2631ndash2637 2009
[4] J Liang Y Li Y Huang et al ldquoSodium borohydride hydrolysison highly efficient Co-BPd catalystsrdquo International Journal ofHydrogen Energy vol 33 no 15 pp 4048ndash4054 2008
[5] U B Demirci O Akdim J Andrieux J Hannauer RChamoun and P Miele ldquoSodium borohydride hydrolysis ashydrogen generator Issues state of the art and applicabilityupstream froma fuel cellrdquo Fuel Cells vol 10 no 3 pp 335ndash3502010
[6] US Department of Energy Hydrogen Program 2007httpwwwhydrogenenergygov
[7] U B Demirci and P Miele ldquoSodium borohydride versusammonia borane in hydrogen storage and direct fuel cellapplicationsrdquo Energy and Environmental Science vol 2 no 6pp 627ndash637 2009
[8] B H Liu and Z P Li ldquoA review Hydrogen generation fromborohydride hydrolysis reactionrdquo Journal of Power Sources vol187 no 2 pp 527ndash534 2009
[9] S Cavaliere J Hannauer U B Demirci O Akdim and PMieleldquoEx situ characterization of N
2H4- NaBH
4- and NH
3BH3-
reduced cobalt catalysts used in NaBH4hydrolysisrdquo Catalysis
Today vol 170 no 1 pp 3ndash12 2011[10] H I Schlesinger E R Brown A E Finholitam J R Gilbreathh
H R Hoekstra and E A Hyde ldquoProcedures for the preparationof methyl boraterdquo Journal of American Chemical Society vol 75no 1 pp 213ndash215 1953
[11] A M Ozerova V I Simagina O V Komova et al ldquoCobaltborate catalysts for hydrogen production via hydrolysis ofsodium borohydriderdquo Journal of Alloys and Compounds vol513 pp 266ndash272 2012
[12] S U Jeong R K Kim E A Cho et al ldquoA study on hydrogengeneration from NaBH
4solution using the high-performance
Co-B catalystrdquo Journal of Power Sources vol 144 no 1 pp 129ndash134 2005
[13] R Khan S W Kim T-J Kim and C-M Nam ldquoComparativestudy of the photocatalytic performance of boron-iron Co-doped and boron-doped TiO
2nanoparticlesrdquoMaterials Chem-
istry and Physics vol 112 no 1 pp 167ndash172 2008[14] A Kanturk Figen and B Coskuner ldquoA novel perspective for
hydrogen generation from ammonia borane (NH3BH3) with
Co-B catalysts lsquoultrasonic Hydrolysisrsquordquo International Journal ofHydrogen Energy vol 38 no 6 pp 2824ndash2835 2013
[15] C C Yang M S Chen and Y W Chen ldquoHydrogen generationby hydrolysis of sodium borohydride on CoBSiO
2catalystrdquo
International Journal ofHydrogenEnergy vol 36 no 2 pp 1418ndash1423 2011
[16] R Patil P Bhoir P Deshpande T Wattamwar M Shirude andP Chaskar ldquoRelevance of sonochemistry or ultrasound (US)as a proficient means for the synthesis of fused heterocyclesrdquoUltrasonics Sonochemistry vol 20 no 6 pp 1327ndash1336 2013
[17] T Q Liu O Sakurai N Mizutani and M Kato ldquoPreparationof spherical fine ZnO particles by the spray pyrolysis methodusing ultrasonic atomization techniquesrdquo Journal of MaterialsScience vol 21 no 10 pp 3698ndash3702 1986
[18] S L Che K Takada K Takashima O Sakurai K Shinozakiand N Mizutani ldquoPreparation of dense spherical Ni particlesand hollow NiO particles by spray pyrolysisrdquo Journal of Materi-als Science vol 34 no 6 pp 1313ndash1318 1999
[19] C L Bianchi E Gotti L Toscano and V Ragaini ldquoPreparationof PdC catalysts via ultrasound a study of the metal distribu-tionrdquo Ultrasonics Sonochemistry vol 4 no 4 pp 317ndash320 1997
[20] S S Ostapenko L Jastrzebski J Lagowski and B SoporildquoIncreasing short minority carrier diffusion lengths in solar-grade polycrystalline silicon by ultrasound treatmentrdquo AppliedPhysics Letters vol 65 no 12 pp 1555ndash1557 1994
[21] M Run SWu andGWu ldquoUltrasonic synthesis ofmesoporousmolecular sieverdquo Microporous and Mesoporous Materials vol74 no 1-3 pp 37ndash47 2004
[22] U R Pillai E Sahle-Demessie and R S Varma ldquoAlterna-tive routes for catalyst preparation use of ultrasound andmicrowave irradiation for the preparation of vanadium phos-phorus oxide catalyst and their activity for hydrocarbon oxida-tionrdquo Applied Catalysis A General vol 252 no 1 pp 1ndash8 2003
[23] H LiH Li J ZhangWDai andMQiao ldquoUltrasound-assistedpreparation of a highly active and selective Co-B amorphousalloy catalyst in uniform spherical nanoparticlesrdquo Journal ofCatalysis vol 246 no 2 pp 301ndash307 2007
[24] M G Sulman ldquoEffects of ultrasound on catalytic processesrdquoRussian Chemical Reviews vol 69 no 2 pp 165ndash177 2000
[25] H Li J Zhang and H Li ldquoUltrasound-assisted preparationof a novel Ni-B amorphous catalyst in uniform nanoparticlesfor p-chloronitrobenzene hydrogenationrdquo Catalysis Communi-cations vol 8 no 12 pp 2212ndash2216 2007
[26] A J Hung S F Tsai Y Y Hsu J R Ku Y H Chen and CC Yu ldquoKinetics of sodium borohydride hydrolysis reaction forhydrogen generationrdquo International Journal ofHydrogen Energyvol 33 no 21 pp 6205ndash6215 2008
[27] O Levenspiel Chemical Reaction Engineering John Wiley ampSons New York NY USA 3rd edition 1999
[28] L Jun X Shuping and G Shiyang ldquoFT-IR and Ramanspectroscopic study of hydrated boratesrdquo Spectrochimica ActaA Molecular Spectroscopy vol 51 no 4 pp 519ndash532 1995
[29] A Kanturk M Sari and S Piskin ldquoSynthesis crystal structureand dehydration kinetics of NaB(OH)
4sdot2H2Ordquo Korean Journal
of Chemical Engineering vol 25 no 6 pp 1331ndash1337 2008[30] Q Zhang Y Wu X Sun and J Ortega ldquoKinetics of catalytic
hydrolysis of stabilized sodium borohydride solutionsrdquo Indus-trial and Engineering Chemistry Research vol 46 no 4 pp1120ndash1124 2007
[31] J Andrieux D Swierczynski L Laversenne et al ldquoAmultifactorstudy of catalyzed hydrolysis of solidNaBH
4on cobalt nanopar-
ticles thermodynamics and kineticsrdquo International Journal ofHydrogen Energy vol 34 no 2 pp 938ndash951 2009
[32] B H Liu Z P Li and S Suda ldquoNickel- and cobalt-basedcatalysts for hydrogen generation by hydrolysis of borohydriderdquoJournal of Alloys and Compounds vol 415 no 1-2 pp 288ndash2932006
[33] W Ye H Zhang D Xu L Ma and B Yi ldquoHydrogen generationutilizing alkaline sodium borohydride solution and supportedcobalt catalystrdquo Journal of Power Sources vol 164 no 2 pp 544ndash548 2007
[34] J Zhao H Ma and J Chen ldquoImproved hydrogen generationfrom alkaline image solution using carbon-supported image ascatalystsrdquo International Journal of Hydrogen Energy vol 32 no18 pp 4711ndash4716 2007
Journal of Chemistry 9
[35] H Tian Q Guo and D Xu ldquoHydrogen generation fromcatalytic hydrolysis of alkaline sodium borohydride solutionusing attapulgite clay-supported Co-B catalystrdquo Journal ofPower Sources vol 195 no 8 pp 2136ndash2142 2010
[36] C H Liu B H Chen C L Hsueh J R Ku M S Jeng and FTsau ldquoHydrogen generation from hydrolysis of sodium boro-hydride using Ni-Ru nanocomposite as catalystsrdquo InternationalJournal of Hydrogen Energy vol 34 no 5 pp 2153ndash2163 2009
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
8 Journal of Chemistry
[2] R Retnamma A Q Novais and C M Rangel ldquoKinetics ofhydrolysis of sodium borohydride for hydrogen productionin fuel cell applications a reviewrdquo International Journal ofHydrogen Energy vol 36 no 16 pp 9772ndash9790 2011
[3] O Akdim U B Demirci D Muller and P Miele ldquoCobalt(II) salts performing materials for generating hydrogen fromsodiumborohydriderdquo International Journal of Hydrogen Energyvol 34 no 6 pp 2631ndash2637 2009
[4] J Liang Y Li Y Huang et al ldquoSodium borohydride hydrolysison highly efficient Co-BPd catalystsrdquo International Journal ofHydrogen Energy vol 33 no 15 pp 4048ndash4054 2008
[5] U B Demirci O Akdim J Andrieux J Hannauer RChamoun and P Miele ldquoSodium borohydride hydrolysis ashydrogen generator Issues state of the art and applicabilityupstream froma fuel cellrdquo Fuel Cells vol 10 no 3 pp 335ndash3502010
[6] US Department of Energy Hydrogen Program 2007httpwwwhydrogenenergygov
[7] U B Demirci and P Miele ldquoSodium borohydride versusammonia borane in hydrogen storage and direct fuel cellapplicationsrdquo Energy and Environmental Science vol 2 no 6pp 627ndash637 2009
[8] B H Liu and Z P Li ldquoA review Hydrogen generation fromborohydride hydrolysis reactionrdquo Journal of Power Sources vol187 no 2 pp 527ndash534 2009
[9] S Cavaliere J Hannauer U B Demirci O Akdim and PMieleldquoEx situ characterization of N
2H4- NaBH
4- and NH
3BH3-
reduced cobalt catalysts used in NaBH4hydrolysisrdquo Catalysis
Today vol 170 no 1 pp 3ndash12 2011[10] H I Schlesinger E R Brown A E Finholitam J R Gilbreathh
H R Hoekstra and E A Hyde ldquoProcedures for the preparationof methyl boraterdquo Journal of American Chemical Society vol 75no 1 pp 213ndash215 1953
[11] A M Ozerova V I Simagina O V Komova et al ldquoCobaltborate catalysts for hydrogen production via hydrolysis ofsodium borohydriderdquo Journal of Alloys and Compounds vol513 pp 266ndash272 2012
[12] S U Jeong R K Kim E A Cho et al ldquoA study on hydrogengeneration from NaBH
4solution using the high-performance
Co-B catalystrdquo Journal of Power Sources vol 144 no 1 pp 129ndash134 2005
[13] R Khan S W Kim T-J Kim and C-M Nam ldquoComparativestudy of the photocatalytic performance of boron-iron Co-doped and boron-doped TiO
2nanoparticlesrdquoMaterials Chem-
istry and Physics vol 112 no 1 pp 167ndash172 2008[14] A Kanturk Figen and B Coskuner ldquoA novel perspective for
hydrogen generation from ammonia borane (NH3BH3) with
Co-B catalysts lsquoultrasonic Hydrolysisrsquordquo International Journal ofHydrogen Energy vol 38 no 6 pp 2824ndash2835 2013
[15] C C Yang M S Chen and Y W Chen ldquoHydrogen generationby hydrolysis of sodium borohydride on CoBSiO
2catalystrdquo
International Journal ofHydrogenEnergy vol 36 no 2 pp 1418ndash1423 2011
[16] R Patil P Bhoir P Deshpande T Wattamwar M Shirude andP Chaskar ldquoRelevance of sonochemistry or ultrasound (US)as a proficient means for the synthesis of fused heterocyclesrdquoUltrasonics Sonochemistry vol 20 no 6 pp 1327ndash1336 2013
[17] T Q Liu O Sakurai N Mizutani and M Kato ldquoPreparationof spherical fine ZnO particles by the spray pyrolysis methodusing ultrasonic atomization techniquesrdquo Journal of MaterialsScience vol 21 no 10 pp 3698ndash3702 1986
[18] S L Che K Takada K Takashima O Sakurai K Shinozakiand N Mizutani ldquoPreparation of dense spherical Ni particlesand hollow NiO particles by spray pyrolysisrdquo Journal of Materi-als Science vol 34 no 6 pp 1313ndash1318 1999
[19] C L Bianchi E Gotti L Toscano and V Ragaini ldquoPreparationof PdC catalysts via ultrasound a study of the metal distribu-tionrdquo Ultrasonics Sonochemistry vol 4 no 4 pp 317ndash320 1997
[20] S S Ostapenko L Jastrzebski J Lagowski and B SoporildquoIncreasing short minority carrier diffusion lengths in solar-grade polycrystalline silicon by ultrasound treatmentrdquo AppliedPhysics Letters vol 65 no 12 pp 1555ndash1557 1994
[21] M Run SWu andGWu ldquoUltrasonic synthesis ofmesoporousmolecular sieverdquo Microporous and Mesoporous Materials vol74 no 1-3 pp 37ndash47 2004
[22] U R Pillai E Sahle-Demessie and R S Varma ldquoAlterna-tive routes for catalyst preparation use of ultrasound andmicrowave irradiation for the preparation of vanadium phos-phorus oxide catalyst and their activity for hydrocarbon oxida-tionrdquo Applied Catalysis A General vol 252 no 1 pp 1ndash8 2003
[23] H LiH Li J ZhangWDai andMQiao ldquoUltrasound-assistedpreparation of a highly active and selective Co-B amorphousalloy catalyst in uniform spherical nanoparticlesrdquo Journal ofCatalysis vol 246 no 2 pp 301ndash307 2007
[24] M G Sulman ldquoEffects of ultrasound on catalytic processesrdquoRussian Chemical Reviews vol 69 no 2 pp 165ndash177 2000
[25] H Li J Zhang and H Li ldquoUltrasound-assisted preparationof a novel Ni-B amorphous catalyst in uniform nanoparticlesfor p-chloronitrobenzene hydrogenationrdquo Catalysis Communi-cations vol 8 no 12 pp 2212ndash2216 2007
[26] A J Hung S F Tsai Y Y Hsu J R Ku Y H Chen and CC Yu ldquoKinetics of sodium borohydride hydrolysis reaction forhydrogen generationrdquo International Journal ofHydrogen Energyvol 33 no 21 pp 6205ndash6215 2008
[27] O Levenspiel Chemical Reaction Engineering John Wiley ampSons New York NY USA 3rd edition 1999
[28] L Jun X Shuping and G Shiyang ldquoFT-IR and Ramanspectroscopic study of hydrated boratesrdquo Spectrochimica ActaA Molecular Spectroscopy vol 51 no 4 pp 519ndash532 1995
[29] A Kanturk M Sari and S Piskin ldquoSynthesis crystal structureand dehydration kinetics of NaB(OH)
4sdot2H2Ordquo Korean Journal
of Chemical Engineering vol 25 no 6 pp 1331ndash1337 2008[30] Q Zhang Y Wu X Sun and J Ortega ldquoKinetics of catalytic
hydrolysis of stabilized sodium borohydride solutionsrdquo Indus-trial and Engineering Chemistry Research vol 46 no 4 pp1120ndash1124 2007
[31] J Andrieux D Swierczynski L Laversenne et al ldquoAmultifactorstudy of catalyzed hydrolysis of solidNaBH
4on cobalt nanopar-
ticles thermodynamics and kineticsrdquo International Journal ofHydrogen Energy vol 34 no 2 pp 938ndash951 2009
[32] B H Liu Z P Li and S Suda ldquoNickel- and cobalt-basedcatalysts for hydrogen generation by hydrolysis of borohydriderdquoJournal of Alloys and Compounds vol 415 no 1-2 pp 288ndash2932006
[33] W Ye H Zhang D Xu L Ma and B Yi ldquoHydrogen generationutilizing alkaline sodium borohydride solution and supportedcobalt catalystrdquo Journal of Power Sources vol 164 no 2 pp 544ndash548 2007
[34] J Zhao H Ma and J Chen ldquoImproved hydrogen generationfrom alkaline image solution using carbon-supported image ascatalystsrdquo International Journal of Hydrogen Energy vol 32 no18 pp 4711ndash4716 2007
Journal of Chemistry 9
[35] H Tian Q Guo and D Xu ldquoHydrogen generation fromcatalytic hydrolysis of alkaline sodium borohydride solutionusing attapulgite clay-supported Co-B catalystrdquo Journal ofPower Sources vol 195 no 8 pp 2136ndash2142 2010
[36] C H Liu B H Chen C L Hsueh J R Ku M S Jeng and FTsau ldquoHydrogen generation from hydrolysis of sodium boro-hydride using Ni-Ru nanocomposite as catalystsrdquo InternationalJournal of Hydrogen Energy vol 34 no 5 pp 2153ndash2163 2009
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Journal of Chemistry 9
[35] H Tian Q Guo and D Xu ldquoHydrogen generation fromcatalytic hydrolysis of alkaline sodium borohydride solutionusing attapulgite clay-supported Co-B catalystrdquo Journal ofPower Sources vol 195 no 8 pp 2136ndash2142 2010
[36] C H Liu B H Chen C L Hsueh J R Ku M S Jeng and FTsau ldquoHydrogen generation from hydrolysis of sodium boro-hydride using Ni-Ru nanocomposite as catalystsrdquo InternationalJournal of Hydrogen Energy vol 34 no 5 pp 2153ndash2163 2009
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of