Mike LyonsMike LyonsTrinity Electrochemical Energy Conversion & Electrocatalysis Group

School of ChemistryTrinity College

Dublin 2melyons@tcd.ie

Lecture Overview

� Electrochemical Science & Hydrogen Economy� Oxygen electrochemistry kinetically limits operation

in water electrolysis and fuel cell devices.� Oxygen electrode reactions (OER, ORR) are complex � Oxygen electrode reactions (OER, ORR) are complex

multistep processes. Require careful kinetic analysis for full mechanistic understanding for device optimization.

� Hydrous oxide formation via cyclic potential multicycling (CPM) generates useful materials for pH sensing and OER .

� Analysis of OER kinetics and mechanism for Fe and Ni electrode materials in aqueous base.

Energy: ‘the moon shot of our generation’

• “Energy is the single most important challenge facing humanity today.” Nobel Laureate Rick Smalley, April 2004, Testimony to U.S. Senate.

• ‘‘..energy is the single most important scientific and technological challenge facing humanity in the 21st century..”: Chemical and Engineering News, 21st century..”: Chemical and Engineering News, August 22, 2005.

• “ What should be the centerpiece of a policy of American renewal is blindingly obvious: making a quest for energy independence the moon shot of our generation“, Thomas L. Friedman, New York Times, Sept. 23, 2005.

Electrode ElectrolyteIonically conductingmedium : electrolytesolution, molten salt,solid electrolyte,polymericelectrolyte, etc.

Conductionoccurs via

Electrochemical Science underpinned by interaction of electrons with matter and electrochemical technologies based on consequences of Heterogeneous interfacial electron transfer (HIET).

Electrochemical Science : the essentials

Electronically conducting phase : metal, semiconductor,conducting polymer material etc.

electrolyte, etc.occurs viamigration ofelectrons .Solid statePhysics : energyband theory. Material transport occurs

via migration, diffusionand convection

HIET

The Hydrogen Economy:Hydrogen as an energy carrier.

G.W. Crabtree, M.S. Dresselhaus, M.V. Buchanan, ‘The hydrogen Economy’ Physics Today, Dec.2004, pp.39-45.U. Bossel, ‘Does a hydrogen economy make sense?’ Proc. IEEE, 94 (10)(2006), pp.1826-1836.

http://www.foresight.gov.uk/Energy/hydrogen_and_fuel_cells_towards_a_sustainable_future.pdf

P.P. Edwards, V.L. Kuznetsov, W.I.F. David,N. Brandon. Energy Policy 36(2008) 4356-4362.

Water Electrolysis : electrochemical substance production

Overpotential losses increase net electrical energy needed asinput to drive reactions at electrodes.

Self-driving electrolysis cell

( ) ,e cell C AE i E IRη η= + + +

reactions at electrodes.

Ballard PEM Fuel Cell

Overpotential losses reduce net voltage output.

Self-driving Fuel Cell

( ) iiEP =

( ) ,e cell C AE i E IRη η= − − −

The bottom Line� Water electrolysis device:

� Very sluggish Oxygen Evolution Reaction (OER) kinetics (v. high overpotential) limit device operational effectiveness (higher electrical energy input required)

� Metal oxide materials exhibit useful potential as catalysts for OER and ORR in electrochemical energy conversion devices.

� Major aim of Science Foundation Ireland (SFI) Principal Investigator Programme Grant required)

� Fuel Cell:� Very sluggish Oxygen

Reduction Reaction (ORR) kinetics limit voltage output of device

� For both device types the cathodic Hydrogen Evolution Reaction (HER) or the anodic Hydrogen Oxidation Reaction (HOR) are reasonable kinetically facile.

Investigator Programme Grant Number SFI/10/IN.1/I2969 is to develop cheap and efficient oxide electrode materials for use in water electrolysis and fuel cells.

Transition Metal Oxides� 2 types:

� Compact anhydrous oxides, e.g. rutile, perovskite, spinel.� Oxygen present only as bridging

species between two metal cationsand ideal crystals constitute tightly packed giant molecules.

� Prepared via thermal techniques, e.g decomposition of unstable salt

� Micro-dispersed hydrous oxides� Oxygen is present not just as a

bridging species between metal ions, but also as O-, OH and OH2species in coordinated terminal group form.

� Hydrous oxides in contact with aqueous media contain large quantities of loosely bound and e.g decomposition of unstable salt quantities of loosely bound and trapped water plus electrolyte species.

� Prepared via base precipitation, electrochemical techniques.

� Materials are prepared in kinetically most accessible rather than thermodynamically most stable form.

� Are often amorphous or only poorly crystalline and prone to rearrangement.

L. D. Burke, M.E.G. Lyons, Modern Aspects Electrochemistry, 18 (1986)169-248.

Geothite FeOOH

Fe + OH- → FeOH(ads.) + 2e-

FeH(ads.) → Fe + H+ + e-

A1

FeOH(ads.) + OH- → Fe(OH)2 + e-

FeOH(ads.) + OH- → FeO + H2O + e-A2

A0: OER

Surface redox chemistry: Bright Fe electrode

3Fe(OH)2 + 2OH- → Fe3O4 + 4H2O + 2e-

3FeO + 2OH- → Fe3O4 + H2O + 2e-A4

In situ RamanEQCMRRDE

[Fe2(OH)6·3H2O]2- + 3OH- → [Fe2(OH)9]3- +3H2O + 2e-

A3/C2

[Fe(OH)3.5 •nH2O]0.5- •(Na+)0.5 + e- � Fe(OH)2•n H2O + 0.5 Na+ + 1.5OH-

FeO.FeOOH + H2O + 3e- → Fe + FeO22- + H2O + OH-

C1

C0: HER

RRDE

Greater fine structureobserved at low sweeprate.

Hydrous Oxide Growth via Cyclic Potential Multicycling (CPM)Procedure of Fe electrode in aqueous alkaline solution.

Layer growth parameters:• Upper, lower potential sweep limits.

• Solution temperature.• Solution pH.• Potential sweep rate.• Base concentration.

N

A3

0.5 M NaOH

Hydrous oxide film regarded as a surfacebonded polynuclear species. Metal cationsin polymeric network held together by sequence of oxy and hydroxy bridges.Mixed conduction (electronic, ionic) behaviour similar to that exhibited by

C2

0.5 M NaOH

Lyons, Burke, J. Electroanal. Chem., 170 (1984) 377-381Lyons, Burke, J. Electroanal. Chem., 198 (1986) 347-368Lyons, Brandon Phys. Chem. Chem. Phys., 11 (2009) 2203-2217Lyons, Doyle, Brandon, Phys. Chem. Chem. Phys., 2011 DOI: 10.1039/c1cp22470k

Mixed conduction (electronic, ionic) behaviour similar to that exhibited by Polymer Modified Electrodes.Can regard microdispersed hydrous oxide layer asopen porous mesh of interconnected surfaquometal oxy groups.

Q/ m

C c

m-2

60

80

100

120

Q=a(1-exp(-bN))Hydrous oxide growth kinetics

Cha

rge

/ C

0.010

0.012

0.014

0.016

Murphy Ph.D Thesis UCC 1981

Fe wire electrode, 1.0 M NaOH Inlaid Fe foil electrode, 0.5 M NaOH

N

0 200 400 600

Q/ m

C c

m

0

20

40

60

R=0.9947, R2 = 0.9895a = 103.94 ± 6.05 mC/cm2

b = 0.0044 ± 0.0006 cycle-1

Number of Growth Cycles

0 100 200 300 400 500

Cha

rge

/ C

0.000

0.002

0.004

0.006

0.008

Lyons, Doyle, Brandon, PCCP 2011,

CPM Methodology reproducible across space and time.

R = 0.9935, R2 = 0.9870a = 0.0136 ± 0.0003 Cb = 0.0156 ± 0.0011 cycle-1

CPM methodology is scalable : oxide growth process does not dependon electrode size. Important for commercial viability.

Cur

rent

(A

)

0.002

0.004

0.006

0.008

0.010

0 cycles75 cycles150 cycles

Hydrous oxide growth : Multicycled Ni electrode, 1.0 M NaOH.

Potential (V)

-1.5 -1.0 -0.5 0.0 0.5 1.0

Cur

rent

(A

)

-0.006

-0.004

-0.002

0.000

ββββ-NiOOH

γγγγOxidation state 2.7 - 3.0

Oxidation state 3.5 - 3.67

oxid

atio

n

Charge

Charge

Discharge

Discharge

Overcharge

A2

A2* C2*

- NiOOH

E / V (vs Hg/HgO)

-1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8

I / A

-0.0015

-0.0010

-0.0005

0.0000

0.0005

0.0010

0.0015

0.0020

N

Hydrous oxide growth via CPS method: Ni electrodes, aqueous base (1M NaOH).

αααα-Ni(OH)2ββββ-Ni(OH)2Oxidation state 2.0 - 2.2

Oxidation state 2.0 - 2.2

redu

ctio

n

Ageing

Charge Discharge A2C2pH > 14

Redox switching in Nickel oxide film.

Maria O’Brien, Lisa Russell, Unpublished work August 2011

Inte

grat

ed c

harg

e ca

paci

ty Q

0.0008

0.0010

0.0012

0.0014

0.0016

Hydrous oxide growth via CPM : Multicycled Ni electrode, 1.0 M NaOH.

Q=a(1-exp[-bN])

Number of Cycles N

0 100 200 300 400 500

Inte

grat

ed c

harg

e ca

paci

ty Q

0.0000

0.0002

0.0004

0.0006

Q vs NExperimental data95% Confidence Band 95% Prediction Band

R2 = 0.979a = 0.001±5.79x10-5Cb=0.0058±0.0005 cycle-1

Q/C 0.0008

0.0010

0.0012

0.0014

0.0016

Hydrous oxide growth via CPM : Multicycled Ni electrode, 1.0 M NaOH.

Q=a(1-exp[-bN])

N

0 100 200 300 400 500

Q/C

0.0000

0.0002

0.0004

0.0006Q versus NExperimental data95% Confidence Band 95% Prediction Band

R = 0.9869, R2 = 0.9739a = 0.0014±7.43x10-5Cb=0.045±0.0004 cycle-1

Cha

rge

/ C

0.008

0.010

0.012

0.014

0.016

NickelIronIronIron Aged Fe Electrode

Comparing hydrous oxide growth via CPM on Fe and Ni substrates.

No. of Growth Cycles

0 50 100 150 200 250 300 350 400 450

Cha

rge

/ C

0.000

0.002

0.004

0.006

0.008New Fe Electrode

New Ni Electrode

Fe hydrous oxide grows via CPM more readily and to greater thickness than Ni.Doyle, Godwin, unpublished data Nov. 2011.

[M2O3 (OH)3 (OH2)3]n3- + 3nOH- �

[MO2(OH)2(OH2)2]2n2- + 3nH2O + 2ne-

M(IV)

M(III)

Redox switching involves topotactic charge storage reactions in open hydrous oxide layer whichBehaves as ion exchange membrane.Hydrated counter/co-ions (M+, H+, OH- assumed present in pores and channels of film to balancenegative charge on polymer chain.Equivalent circuit model: dual/multi- rail

Super-Nernstian Redox Potentialvs pH shift related to hydrolysis effects in hydrous layer yieldinganionic oxide structures.

M = Ir, Rh

dE/dpH = -3ρ/2

Rhodium oxide

Redox switching chemistry: hydrous oxideLayer, Mixed conduction mechanism:ion/electron transfer.

[Fe2(OH)6(OH2)3]2- + 3OH- �

[Fe2O3(OH)3(OH2)3]3- + 3H2O + 2e-

Fe(II)

Fe(III)

Equivalent circuit model: dual/multi- rail Transmission Line as done for ECP films..

L.D. Burke, M.E.G. Lyons, E.J.M.O’Sullivan, D.P. Whelan J. Electroanal. Chem., 122 (1981) 403.

dE/dpH = -3ρ/2

ρ= 2.303RT/Fρ= -88.5 mV/decT = 298K

Iron oxide

Fe(III) Oxidized form yellow-green

Fe(II) Reduced form transparent

Pea

k P

oten

tial /

V v

s. H

g/H

gO

-0.2

0.0

0.2

Variation of hydrous Fe oxide peak A3 potential with solution pH.

Super-Nernstian shift

pH

8 9 10 11 12 13 14

Pea

k P

oten

tial /

V v

s. H

g/H

gO

-0.8

-0.6

-0.4

Experiment 1 (120 cycles) Experiment 2 (120 cycles)Experiment 3 (120 cycles)Slope = 0.10 V/pH unit

Doyle, unpublished data Nov. 2011

Metal oxide wire pH sensor spinoff.

Super-Nernstian pH shift signifies possible development of more sensitive and scalable metal oxide wire pH sensors.

pH

ENernstian

Super-Nernstian

Enhanced sensitivity of sensorto given pH change.Sensor probe can be made very smallfor biomedical applications.

� Kinetically limiting step in water electrolysis cells and PEM fuel cell.

� Multistep multi-electron transfer reaction involving adsorbed intermediates.

� Overall reaction (alkaline medium)

O2 + 2H2O + 4e- � 4OH-

E0 = 0.303 V (vs. Hg/HgO)

� Krasil’shchikov (1963)

S + OH- � SOHad + e-

SOHad + OH- � SO-ad + H2O

� Depending on RDS can explain a variety of Tafel slopes.

� Modification permits concept of formation/decomposition of higher oxide – e.g. for Ni

OH-� OHad+ e-

OHad+ OH- � O-ad+ H2O

2 β-NiOOH + O-ad � 2NiO2+ H2O + e-

2NiO2 + H2O � 2 β-NiOOH + Oad

Oad+ Oad→ O2

Anodic Oxygen Evolution Reaction (OER)

SOHad + OH � SO ad + H2OSO-

ad� SOad + e-

2SOad → 2S + O2

� Bockris Electrochemical Oxide (1956)S + OH- � SOHad + e-

SOHad + OH- � SO + H2O + e-

SO + SO � 2S + O2

� Krasil’shchikov/modification thereof, is pathway most often proposed for OER on metal / metal-oxide electrodes in alkaline solution.

� OER at oxidized metal and metal oxide electrodes involves active participation of oxide.

� Acid/base behaviour of oxide important consideration .

� Concept of active surface or surfaquo groups important.

Embedded metal (Fe/Ni) foil workingelectrode

Temp. control unit.Multi function electrochemicalworkstation

EC cell

Active oxygen evolutionFe foil workingelectrodePotential / V vs. Hg/HgO

0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05

Log

(Cur

rent

Den

sity

i / A

cm

-2)

-4.0

-3.5

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

uncyled120 cycles60 mV dec-1

120 mV dec-1

Reference Electrode

Tafel Plot

Charge Q / C cm-2

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14

Taf

el s

lope

/ m

V d

ec-1

35

40

45

50

55

60

65

New Fe electrode'Aged' Fe electrode

Potential / V vs. Hg/HgO

0.6 0.7 0.8 0.9 1.0 1.1

Log

(Cur

rent

/ A

)

-5.5

-5.0

-4.5

-4.0

-3.5

-3.0

-2.5

-2.0

-1.5

Uncycled 30 cycles 60 cycles 120 cycles 180 cycles 240 cycles 300 cycles

Anodic OER, Fe aqueous alkaline solution.

Tafel Plots

Charge Q / C cm-2

Charge Q / C cm-2

0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09

Cur

rent

Den

sity

i / A

cm

-2

0.060

0.065

0.070

0.075

0.080

0.085

0.090

0.85 V

Potential / V vs. Hg/HgO

Charge Q / C cm-2

0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09

Pot

entia

l / V

vs.

Hg/

HgO

0.695

0.700

0.705

0.710

0.715

0.720

0.725

1 mA cm-2

Hydrous Iron Oxide Electrodes.OER Reaction Order Studies

Log

(i / A

cm

-2)

-4

-3

-2

-1

0

0.1 M0.5 M1.0 M2.0 M5.0 M

60 mV dec-1

120 mV dec-1

N = 120 cyclesReaction order wrt OH- activity ca. 0.9 (low TS region) and ca. 0.8(high TS region).

Potential / V vs. Hg/HgO

0.5 0.6 0.7 0.8 0.9 1.0 1.1-5

120 mV dec-1

Log (aOH-)

-1.5 -1.0 -0.5 0.0 0.5 1.0

Log

(Cur

rent

Den

sity

i / A

cm

-2)

-4.0

-3.5

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

60 mV dec-1 regionSlope = 0.87120 mV dec-1 regionSlope = 0.81

Measure OER current densityat fixed overpotential fromanalysis of Tafel Plots as function ofOH- ion activity.

E/V

0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1

log(

I/A)

-5

-4

-3

-2

-1

0.1M0.25M0.75M1M 1.5M2M2.5M3M4M5M

I/A

-0.002

0.000

0.002

0.004

0.006

0.1M0.25M0.5M0.75M1M1.5M2M2.5M3M4M

N = 120 cycles

N = 120 cycles

Low potential : TS = 60 mV/dec.High potential : TS = 120 mV/decNi in aqueous base: redox activity

and OER behaviour.

E/V

Tafel Plots for OER at Ni oxide layers grown via potential cycling (N = 120 cycles) in 1.0 M NaOH recorded as function of baseconcentration.

E/V

-0.6 -0.4 -0.2 0.0 0.2 0.4 0.6

E=0.64V

η = 0.337V RegressionConfidence

c = -3.0513507838m = 0.8526502073r ² = 0.96614858

Ni oxide layer grown in 1.0 M NaOH. N = 120 cycles.Reaction order plot, low TafelSlope Region.mOH

- = 0.85.

E=0.71V

η = 0.407VRegressionConfidence

c = -2.1450473735m = 0.8182632348r ² = 0.973540901

Ni oxide layer grown in 1.0 M NaOH. N = 120 cycles.Reaction order plot, high TafelSlope Region.mOH

- = 0.82.

Voltammetric response of hydrousNi oxide film as function of baseConcentration.

Taf

el S

lope

(V

)

0.070

0.075

0.080

0.085

Slope: 0.055041Intercept 22.607r ²: 0.92

log(

I/A)

-3.0

-2.5

-2.0

-1.5

-1.0

Uncycled

Low overpotential Tafel Slope increases with increasing hydrous oxidecharge capacity.

Effect of oxide charge capacity Qon OER catalytic efficiency: Ni inaqueous base.

Charge (C)

0.0000 0.0002 0.0004 0.0006 0.0008 0.0010 0.0012

Taf

el S

lope

(V

)

0.055

0.060

0.065

0.070

Variation of low overpotential Tafel Slope for OER at multicycled Ni oxide Electrode in 1.0 M NaOHas a function of oxide charge capacity Q (thickness).

Ian Godwin, Unpublished work October 2011

Tafel Plot OER as function of hydrous layer thickness (# cycles).Ni oxide electrode, 1M NaOH.

E/V

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1

log(

I/A)

-5.0

-4.5

-4.0

-3.5

-3.0Uncycled

30 Cycles

60 Cycles

120 Cycles

180 Cycles

240 Cycles

Oxygen evolution rate at fixed potential at oxide coated Ni in 1.0 MNaOH as function of redox charge storage capacity of hydrous layer.

η=0.337V

η=0.347V

η=0.357V

Maria O’Brien, Lisa Russell, Unpublished work August 2011

Assuming Langmuir adsorption conditions with step II rate determining:

[Fe(VI)Om(OH)n(OH2)y]p- + OH- [Fe(VI)Om(OH)n(OH*)(OH2)y-1]

p-

+ H2O + e-

Kinetic parameters:

•Low overpotentials – Tafel slope of 60 mV dec-1 decreasing to 40 mV dec-1 for very thick films (Fe). Tafel slope increases from ca. 55 mV dec-1 to ca. 80 mV dec-1 for very thick films(Ni).

•High overpotentials – Tafel slope of 120 mV dec-1 (Multicycled Fe & Ni electrodes)

•Reaction order mOH- ≈ 1 for both Tafel regions (Multicycled Fe & Ni electrodes)

Proposed OER Mechanism

Net reaction flux is given by,

Applying a quasi steady state approximation to SOH we get,

Now assuming the heterogeneous electrochemical rate constants obey the Butler-Volmerequation:

[Fe(VI)Om(OH)n(OH*)(OH2)y-1]p- [Fe(VI)Om(OH)n+1(OH2)y-1]

p-

Assuming Langmuir adsorption conditions with step II rate determining:

[Fe(VI)Om(OH)n(OH2)y]p- + OH- [Fe(VI)Om(OH)n(OH*)(OH2)y-1]

p-

+ H2O + e-

Kinetic parameters:

•Low overpotentials – Tafel slope of 60 mV dec-1 decreasing to 40 mV dec-1 for very thick films.

•High overpotentials – Tafel slope of 120 mV dec-1

•Reaction order mOH- ≈ 1 for both Tafel regions

Proposed OER Mechanism

At low overpotentials: k20 << k-1

0

[Fe(VI)Om(OH)n(OH*)(OH2)y-1]p- [Fe(VI)Om(OH)n+1(OH2)y-1]

p-

At high overpotentials : k20 >> k-1

0

[ ]01 expS OH

f k F RTα β η−Σ ≅ Γ ( ) 12.303 2 120b RT F mVdec−≅ ≅

Step I: RDS at high overpotentials, k20 >> k-1

0

Step II: RDS at low overpotentials, k20 << k-1

0

Step III: RDS at low overpotentials for thick films

[MOm(OH)n(OH2)y]p- + OH- [MOm(OH)n(OH*)(OH2)y-1]

p-

+ H2O + e-

[MOm(OH)n(OH*)(OH2)y-1]p- [MOm(OH)n+1(OH2)y-1]

p-

Mechanism Summary

Step III: RDS at low overpotentials for thick films

Step IV: Active oxygen evolution

Step V: Regeneration

[MOm(OH)n+1(OH2)y-1]p- [MOm(OH)n+1(OH2)y-1]

(p-1)- + e-

[MOm(OH)n+1(OH2)y-1](p-1)-

+ 2OH-

[MOm(OH)n-1(OH2)y-1](p-1)-

+ O2 + 2H2O + 2e-

[MOm(OH)n-1(OH2)y-1](p-1)-

+ OH- + H2O

[MOm(OH)n(OH2)y]p-

M = Fe: p=2m+n-6M= Ni: p= 2m+n-3

Highly reactive octahedral Fe(VI) intermediate proposed.

Tafel Plots OER Multicycled Hydrous Oxide coated Ni and FeElectrodes (N = 120 cycles), 1.0 M Base, 298 K.

Log

(Cur

rent

den

sity

/ A

cm

-2)

-2

-1

0

Nickel (120 growth cycles)Iron (120 growth cycles)

η∆

Ni has reduced overpotential for OER onsetcompared with Fe.

Overpotential (η)

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Log

(Cur

rent

den

sity

/ A

cm

-5

-4

-3

[OH-] = 1.0 M

η∆

Tafel Plots OER Oxidized Ni and FeElectrodes (not multicycled), 1.0 M Base, 298 K.

Lyons, Brandon Int. J. Electrochem. Sci., 3 (2008) 1463-1503.

Tafel Plots OER Oxidized Ni and FeElectrodes (not multicycled), 1.0 M Base, 298 K.

Lyons, Brandon Int. J. Electrochem. Sci., 3 (2008) 1463-1503.

Concluding Comments� Reproducible and scalable methodology developed for generation of

hydrated Fe & Ni metal oxide thin films in aqueous base.

� Duplex layer model proposed for structure of oxide/solution interface region.

� Redox switching characteristics & electrocatalytric kinetics and mechanism with respect to anodic OER at Ni and Fe electrodes in aqueous base evaluated and quantified.

� Novel anodic water splitting OER mechanism proposed involving surfaquo� Novel anodic water splitting OER mechanism proposed involving surfaquogroups in hydrous oxide layer.

� Hydrous oxide thin films exhibit super-Nernstian shifts in redoxpotential with respect to changes in solution pH value. Implying commercial spinoff potential for new generation metal wire pH sensors for use in biomedical applications.

� Fe and Ni oxide materials are cheap and effective electrode materials for anodic water splitting.

� Next stage is to examine application of these oxide materials to Cathodic Oxygen Reduction Reaction (ORR). This is totally unexplored to date.

� 5-6 papers published in year 1 of project.

Publications 2011.� Measuring the electrical conductivity of

single fibres, Serge Rebouillat, Michael E.G.Lyons, Int. J. Electrochem. Sci., 6 (2011) 5731-5740.

� Enhanced oxygen evolution at hydrous oxy-hydroxide modified iron electrodes in aqueous alkaline solution. Michael E.G. Lyons, and Richard Doyle. Int. J. Electrochem. Sci., 6 (2011)5710-5730.

� Transport and kinetics at amperometricenzyme monolayer and multilayer modified

� Mechanism of oxygen reactions at porous oxide electrodes Part 2. Oxygen evolution at RuO2, IrO2 and IrxRu1-xO2 electrodes in aqueous acid and alkaline solution. Phys. Chem. Chem. Phys., 13 (2011) 5314-5335. Michael E.G. Lyons and Stephane Floquet. This paper has been given hot articlestatus arising from very favourable comment (described as ‘a landmark publication’) during peer review process. enzyme monolayer and multilayer modified

electrodes. Michael E.G. Lyons, Analyst, in preparation. This is an invited article commissioned by the Editor.

� Redox switching and oxygen evolution at hydrous oxy-hydroxide modified nickel electrodes in aqueous alkaline solution. Michael E.G. Lyons, Lisa Russell, Maria O’Brien, Richard L. Doyle, Ian Godwin, Int. J. Electrochem. Sci., in preparation.

publication’) during peer review process.

� Paving the way to the integration of smart nanostructures: Part 2. Nanostructuredmetal oxides for electrocatalysis and energy conversion. Serge Rebouillat and Michael E.G. Lyons, Int. J. Electrochem. Sci., 6 (2011) 5830-5917.

� Redox switching and oxygen evolution at oxidized metal and metal oxide electrodes: Iron in base.. Michael E.G. Lyons , Richard L. Doyle, Michael P. Brandon, Phys.Chem. Chem. Phys. 2011, Web Advance Article, DOI: 10.1039/c1cp22470k.

Trinity Electrochemical Energy Conversion & Electrocatalysis (TEECE) Group

� Current Group Personnel:� PI: Prof. Mike Lyons

� PDRF: Dr Richard Doyle

� PG: Mr Ian Godwin

� UG Interns: Ms Maria O’Brien, Ms Lisa Russell

� Group Alumni (Energy Conversion/storage):� Dr Gareth Keeley

� Dr Michael Brandon

� Collaborators: � Prof. Declan Burke, UCC� Prof. Declan Burke, UCC

� Dr Michael Brandon, QUB

� Dr Serge Rebouillat, DuPont Geneva

� Dr Chris Bell, IC London

� Dr Danny O’Hare, IC London

� Prof. Richard Compton, PCL Oxford University

TEECE Group funded by Science Foundation Ireland (SFI) Principal Investigator Programme.

Grant Number SFI/10/IN.1/I2969.Title: Redox and catalytic properties of hydrated metal oxideelectrodes for use in energy conversion and storage devices, 2011-2016.