2008 MAFALDA project ANR PAN H OK ?· Cycles application Cycles réels Cycles réels simplifiés Analyse…

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<ul><li><p>Cyc</p><p>les </p><p>app</p><p>licat</p><p>ion</p><p>Cycles rels Cycles relssimplifis</p><p>An</p><p>alys</p><p>est</p><p>atis</p><p>tique</p><p>Cycles relsmodifis</p><p>4 TESTSrf.</p><p>Modificationdes motifs</p><p>Modification de la squencedes motifs</p><p>4 tests par cycle modifi 16 TESTS</p><p>OUI</p><p>Nouveauxessais</p><p>Suggestion de stratgies de </p><p>fonctionnement</p><p>Validationexprimentale</p><p>Cyc</p><p>les </p><p>sim</p><p>ple</p><p>s</p><p>Modification des conditions opratoires :- Tpile (Tmin, Tmax),- P (PH2max/Pair, PH2/Pairmax),- st (stH2max, stair max)</p><p>6 tests par cycle modifi 24 TESTS</p><p>20 TESTS</p><p>Conditions opratoiresmodifies</p><p>MODELISATION</p><p>Impact des Impact des conditionsconditionsde cyclagede cyclage</p><p>Impact des Impact des conditionsconditionsopratoiresopratoires</p><p>MODELISATION Valid ?</p><p>NON</p><p>Lien avec les autres projets : DECODE, DVD-AME, SPACT-80</p><p>Cycles simples, conditions opratoires de lapplication</p><p>Cyc</p><p>les </p><p>app</p><p>licat</p><p>ion</p><p>Cycles rels Cycles relssimplifis</p><p>An</p><p>alys</p><p>est</p><p>atis</p><p>tique</p><p>Cycles relsmodifis</p><p>4 TESTSrf.</p><p>Modificationdes motifs</p><p>Modification de la squencedes motifs</p><p>4 tests par cycle modifi 16 TESTS</p><p>OUI</p><p>Nouveauxessais</p><p>Suggestion de stratgies de </p><p>fonctionnement</p><p>Validationexprimentale</p><p>Cyc</p><p>les </p><p>sim</p><p>ple</p><p>s</p><p>Modification des conditions opratoires :- Tpile (Tmin, Tmax),- P (PH2max/Pair, PH2/Pairmax),- st (stH2max, stair max)</p><p>6 tests par cycle modifi 24 TESTS</p><p>20 TESTS</p><p>Conditions opratoiresmodifies</p><p>MODELISATION</p><p>Impact des Impact des conditionsconditionsde cyclagede cyclage</p><p>Impact des Impact des conditionsconditionsopratoiresopratoires</p><p>MODELISATION Valid ?</p><p>NON</p><p>Lien avec les autres projets : DECODE, DVD-AME, SPACT-80</p><p>Cycles simples, conditions opratoires de lapplication</p><p>Fix-</p><p>+</p><p>Fix-</p><p>Fix-</p><p>Fix-</p><p>Fix-</p><p>Fix-</p><p>++++</p><p>HH++CoCo2+2+</p><p>Compact layerCompact layer</p><p>)),,(( txr</p><p>),( tr</p><p>0=x</p><p>Diffuse layerDiffuse layer</p><p>Lx =</p><p>ir</p><p>Oxide (Oxide (----O)O)</p><p>Intermediate reaction Intermediate reaction speciesspecies</p><p>Adsorbed water Adsorbed water dipolesdipoles</p><p>Surface catalyst layerSurface catalyst layerInner layer Inner layer </p><p>)),(( trFix-</p><p>OO22</p><p>++</p><p>++</p><p>OH 2</p><p>++++</p><p>++++</p><p>++++</p><p>++++</p><p>++++</p><p>++++</p><p>PtPt2+2+</p><p>++++</p><p>ee--</p><p>PtPtzz++, , CoCoyy++</p><p>PtPtzz++, , CoCoyy++</p><p>CC--supportsupport</p><p>IonomerIonomer</p><p>WaterWater</p><p>GDL Channels</p><p>Catalyst nano-particle</p><p>Membrane</p><p>e+</p><p>H</p><p>22 OOH +</p><p>22 OOH +</p><p>Carbon support</p><p>OH 2</p><p>e</p><p>e</p><p>e</p><p>+2Co</p><p>Cathode electrode</p><p>e</p><p>2O</p><p>2O</p><p>2O</p><p>e</p><p>e</p><p>Impregnated ionomer</p><p>+2Pt</p><p>CutCut viewview</p><p>ElectrodeElectrode</p><p>Dr. Alejandro A. FrancoDr. Alejandro A. Franco11**, Dr. Olivier Lemaire, Dr. Olivier Lemaire11, Dr. Laure Guetaz, Dr. Laure Guetaz11, , RomainRomain CoulonCoulon11, Rodrigo Ferreira de Morais, Rodrigo Ferreira de Morais1,41,4, , Dr. Serge Dr. Serge GambarelliGambarelli22, Dr. Vincent Maurel, Dr. Vincent Maurel22, , Dr. Nicolas FouquetDr. Nicolas Fouquet33, Dr. Franck Masset, Dr. Franck Masset33, Dr. David Loffreda, Dr. David Loffreda44, Prof. Philippe Sautet, Prof. Philippe Sautet44</p><p>11CEACEA--Grenoble/LITEN, Grenoble/LITEN, 22CEACEA--Grenoble/INAC, Grenoble/INAC, 33PSA Peugeot CitroPSA Peugeot Citron, n, 44ENS de LyonENS de Lyon--CNRS/CNRS/LaboratoireLaboratoire de de ChimieChimie*Contact: *Contact: alejandro.franco@cea.fralejandro.franco@cea.fr</p><p>A.A. Franco et al., A.A. Franco et al., A Dynamic Mechanistic Model of an A Dynamic Mechanistic Model of an Electrochemical InterfaceElectrochemical Interface, , J. Electrochem.Soc.J. Electrochem.Soc., , 153153, A1053 (2006)., A1053 (2006).</p><p>A.A. Franco et A.A. Franco et al.,al.,AA multimulti--scale dynamic mechanistic model for scale dynamic mechanistic model for transient analysis of PEFCtransient analysis of PEFC Fuel CellsFuel Cells, , 77, 99 (2007). , 99 (2007). </p><p>MAFALDA ProjectMAFALDA Project (Feb09(Feb09--Jan12)Jan12)Experimental and Experimental and MModelingodeling AAnalyses nalyses ffor the or the </p><p>PEFC PEFC AActive ctive LLayers ayers DDegradation egradation AAssessmentssessment</p><p> MEMEPhysMEMEPhys: Invited lectures and oral presentations in about : Invited lectures and oral presentations in about 6464 international conferences international conferences (e.g. (e.g. americanamerican ElectrochemElectrochem. Soc.. Soc., , Int. Soc. ElectrochemistryInt. Soc. Electrochemistry)) all around the world all around the world (e.g. Qu(e.g. Qubec 2005, Vienna 2006, Chicago 2007, Miami 2007, Phoenix 2008, Vbec 2005, Vienna 2006, Chicago 2007, Miami 2007, Phoenix 2008, Vancouver 2008, Seville 2008, San Francisco 2009ancouver 2008, Seville 2008, San Francisco 2009). ). Invited seminars on Invited seminars on MEMEPhysMEMEPhys in high level institutes, e.g. Heidelberg University (2006), Stin high level institutes, e.g. Heidelberg University (2006), Stanford University (2007), British Columbia University (2008), Saanford University (2007), British Columbia University (2008), Santa Barbara (2009). nta Barbara (2009). 5656 publications on publications on MEMEPhysMEMEPhys in peerin peer--reviewed journals (reviewed journals (J. J. ElectrochemElectrochem. Soc.. Soc., , ElectrochemElectrochem. Soc. Trans.. Soc. Trans., , ElectrochimElectrochim. . ActaActa, , Fuel CellsFuel Cells) and proceedings + ) and proceedings + 153153 citationscitations 11 invited book in preparation by Dr. Franco (publisher: Pan Stanfinvited book in preparation by Dr. Franco (publisher: Pan Stanford) +ord) + 11 patent filled from the patent filled from the modelingmodeling results within MAFALDAresults within MAFALDA</p><p>Publications, communications, patents</p><p>OurOurapproachapproach</p><p>advantagesadvantages</p><p>More realistic description More realistic description of of electrocatalysiselectrocatalysis: : </p><p>account for the nonaccount for the non--equilibriumequilibriumphysicochemical environment physicochemical environment </p><p>Feedback instantaneous Feedback instantaneous performance performance degradationdegradation((prediction of durability as function prediction of durability as function of the materials and compositionsof the materials and compositions))</p><p>Bridging spatiotemporal scales with Bridging spatiotemporal scales with reasonable reasonable </p><p>computational efforts computational efforts </p><p>Fast integration of new Fast integration of new physicochemical phenomena physicochemical phenomena </p><p>((study of study of synergies/synergies/interplayingsinterplayings))</p><p>HydrogenHydrogen atomatom</p><p>Equilibrated PtEquilibrated Pt--RhRh nanonano--structures in vacuum and structures in vacuum and in a Hin a H--rich environment:rich environment:</p><p>reconstruction phenomenareconstruction phenomena</p><p>IT</p><p>PA, PCRHA, RHC</p><p>instantaneous Ucell(t)</p><p>Instantaneous cumulative materials losses</p><p>instantaneous local operatingconditions</p><p>instantaneousnano-micro-structure</p><p>Co</p><p>nro</p><p>lpar</p><p>amet</p><p>ers Coupled no-aging </p><p>phenomena</p><p>Coupled aging phenomena</p><p>Coupled agingCoupled agingphenomenaphenomena</p><p>Coupled no agingCoupled no agingphenomenaphenomena</p><p>Transient elementary Transient elementary kineticskinetics</p><p>and electrochemical and electrochemical double layer effectsdouble layer effects</p><p>(MF elementary kinetics + Monte Carlo)(MF elementary kinetics + Monte Carlo)</p><p>Transient transfer phenomena Transient transfer phenomena --charges, Ocharges, O22, water, water--</p><p>MEMEPhysMEMEPhys: : multiscalemultiscale mechanisticmechanistic model of the PEMFC electrochemical processes, scaling up model of the PEMFC electrochemical processes, scaling up abab initio initio concepts into anconcepts into an irreversible thermodynamics framework, accounting for:irreversible thermodynamics framework, accounting for:</p><p> the MEA the MEA physicochemistryphysicochemistry at spatial NANO and MICRO scales (elementary kinetic approach at spatial NANO and MICRO scales (elementary kinetic approach nono ButlerButler--VolmerVolmer equations are used hereequations are used here).). the intrinsic MEA the intrinsic MEA nanomaterialsnanomaterials degradation and couplings between aging mechanismsdegradation and couplings between aging mechanisms</p><p>Coupled agingCoupled agingphenomenaphenomena</p><p>E.g. E.g. elementaryelementary kinetickinetic description of description of Pt Pt electrochemicalelectrochemical agingaging processesprocesses</p><p>E.g. E.g. elementaryelementary kinetickineticdescription of HOR/ORRdescription of HOR/ORR</p><p>PEMFC MEA durability prediction in automotive conditions: engineering challenges</p><p> PEMFC are nonPEMFC are non--equilibrium electrochemical equilibrium electrochemical systems!systems! In PEMFC electrochemistry is dominated by In PEMFC electrochemistry is dominated by nanoscalenanoscale (quantum and interfacial) effects(quantum and interfacial) effects The The nanomaterialsnanomaterials reconstruct even without reconstruct even without polarization!polarization!</p><p> Engineering requirement: Engineering requirement: improvement of PEMFC improvement of PEMFC nanomaterialsnanomaterials in terms of cost, in terms of cost, performance and durability.performance and durability. Physical modeling of the Physical modeling of the nanomaterialsnanomaterials properties and properties and behavior is crucial to suggest behavior is crucial to suggest new operating conditions filling new operating conditions filling these requirements. these requirements. </p><p>OnOn--thethe--flyfly coupling of scales coupling of scales within within MEMEPhysMEMEPhys</p><p>MEMEPhysMEMEPhys algorithm architecture: dual corealgorithm architecture: dual core</p><p>(DFT)(DFT)</p><p>TEM images for 38 wt.% Pt/C (Tanaka) taken after (A) 2 min. (B) TEM images for 38 wt.% Pt/C (Tanaka) taken after (A) 2 min. (B) 22 min. 22 min. (C) 45 min. (D) 65 min. under the electron beam (U=300keV).(C) 45 min. (D) 65 min. under the electron beam (U=300keV).</p><p>CORCOR--driven driven Pt coarseningPt coarsening</p><p>submodelsubmodel</p><p>2 min2 min 22 min22 min</p><p>45 min45 min 65 min65 min</p><p>Project goals and methodology</p><p>Interplaying between aging mechanisms in Interplaying between aging mechanisms in real PEFC operationreal PEFC operation</p><p>Durability-predictive modeling approach MEMEPhys: concepts and applications</p><p>Cell levelCell level</p><p>ATOMIC scaleATOMIC scale</p><p>MESO scaleMESO scale</p><p>NANO scaleNANO scale</p><p>MICRO scaleMICRO scale(CFD)(CFD)(pseudo(pseudo--structural structural </p><p>resolved CFD)resolved CFD)</p><p>Electrochemical Electrochemical dissolution and dissolution and </p><p>ripeningripening</p><p>NANO scaleNANO scale</p><p>(Franco (Franco et alet al nonnon--equilibrium equilibrium </p><p>interfacial theory)interfacial theory)</p><p>Channels</p><p>GDL</p><p>Active Layer</p><p>Membrane</p><p>I(t)I(t)</p><p>(CFD)(CFD)</p><p>Physical Physical parametersparameters</p><p>+H</p><p>+H</p><p>2O</p><p>+H</p><p>e</p><p>e</p><p>22 OOH +</p><p>OH 2</p><p>2O</p><p>Cathode electrodeAnode electrode GDLGDL Membrane</p><p>CO</p><p>2H</p><p>COHOH ++ 22 +2Pt</p><p>+2Pt</p><p>2H</p><p>2O</p><p>+H</p><p>e</p><p>e</p><p>CO CO</p><p>Competition between local ORR and CO-catalyst poisoning</p><p>Cathode catalyst C-support corrosion</p><p>+2Pt</p><p>+2Pt</p><p>+2Pt</p><p>Carbon Support(C)</p><p>e2</p><p>e2</p><p>e2</p><p>e e</p><p>Lx =</p><p>Pt grainPt grain</p><p>Pt oxydation/dissolution/electrochemicalOstwalds ripening</p><p>A.A. Franco et al., A.A. Franco et al., J. J. ElectrochemElectrochem. Soc.. Soc., , 155155 (4) B367 (2008).(4) B367 (2008).</p><p>A. A. Franco et al., A. A. Franco et al., J. J. ElectrochemElectrochem. Soc.. Soc., , 154154 (7) A712 (2007).(7) A712 (2007).</p><p>A.A. Franco et al., A.A. Franco et al., ECS ECS TransTrans.., , 1313 (15) 35 (2008).(15) 35 (2008).</p><p>Pt particlePt particle</p><p>MEMEPhysMEMEPhys model:model: Prediction of synergies between PEM and C Prediction of synergies between PEM and C degradation mechanisms.degradation mechanisms.</p><p>PredictionPrediction of of experimentalexperimental observables observables (e.g. (e.g. polarizationpolarization curvescurves, , potentialpotential vs. vs. </p><p>time, EIStime, EIS))</p><p>Cathode Aged Cathode</p><p>Carbon corrosionCarbon corrosion</p><p>Oxidation/dissolution/ripening of Oxidation/dissolution/ripening of catalyst catalyst nanoparticlesnanoparticles</p><p>BeforeBefore 24h @OCC24h @OCC AfterAfter 24h @OCC24h @OCC</p><p>Catho</p><p>de</p><p>Cath</p><p>ode</p><p>t (h)</p><p>0.10.1--15 A 15 A cyclescycles</p><p>steady state 0.1 Asteady state 0.1 A</p><p>Potential Potential collapsecollapse</p><p>PEM degradation PEM degradation </p><p>5 mCathode</p><p>M embrane</p><p>ht 10000 +</p><p>Catalyst detachment/dissolved Catalyst detachment/dissolved metallic ions crystallization metallic ions crystallization </p><p>Main objectivesMain objectives ::</p><p> to propose a novel approach to propose a novel approach aiming on a deeper aiming on a deeper understanding of the interplaying understanding of the interplaying of the physicochemical of the physicochemical phenomena responsible of the phenomena responsible of the PEFC MEA degradation under PEFC MEA degradation under steadysteady--state and transient state and transient operating conditionsoperating conditions to provide a predictive model to provide a predictive model of PEFC durability under of PEFC durability under automotive operating conditionsautomotive operating conditions</p><p>Atomic Hydrogen on Pt3Ni(111) Bulk Truncate</p><p>Water Molecule on Pt(111)</p><p>Atomic Hydrogen on Pt(111)</p><p>Oxygen on Pt(111)</p><p>OH on Pt(111) OOH on Pt(111)</p><p>Atomic Oxygen on Pt(111)</p><p>Oxygen on Pt3Ni(111) Bulk Truncate</p><p>Atomic Oxygen on Pt3Ni(111) Bulk Truncate</p><p>Atomic Hydrogen on Pt3Ni(111) Skeleton</p><p>Oxygen on Pt3Ni(111) Skeleton</p><p>Atomic Oxygen on Pt3Ni(111) Skeleton</p><p>0 2 4 6 8 10 12</p><p>x 104</p><p>0.1</p><p>0.2</p><p>0.3</p><p>0.4</p><p>0.5</p><p>0.6</p><p>0.7</p><p>0.8</p><p>0.9</p><p>Time (s)</p><p>UC</p><p>ell (</p><p>V)</p><p> I= 0 AI= 0.1 AI = 0.5 AI = 1 AI = 1.5 AI = 2 A</p><p>2 4 6 8 10 12 14 16</p><p>x 104</p><p>0</p><p>0.2</p><p>0.4</p><p>0.6</p><p>0.8</p><p>1</p><p>Time (s)</p><p>UC</p><p>ell </p><p>(V)</p><p>I= 0 AI= 0.1 AI = 0.5 AI = 1 AI = 1.5 AI = 2 A</p><p>610610</p><p>0 0.5 1 1.5 2</p><p>x 105</p><p>-10</p><p>0</p><p>10</p><p>20</p><p>30</p><p>40</p><p>50</p><p>Time (s)</p><p>C lo</p><p>ss (%</p><p>)</p><p>25 m (PEM + C degradation)50 m (PEM + C degradation)25 m (C degradation)50 m (C degradation)</p><p>0 0.5 1 1.5 2</p><p>x 105</p><p>0</p><p>0.01</p><p>0.02</p><p>0.03</p><p>0.04</p><p>0.05</p><p>0.06</p><p>Time (s)</p><p>SP</p><p>t (m</p><p>-2)</p><p>25 m (PEM + C degradation)50 m (PEM + C degradation)25 m (C degradation)50 m (C degradation)</p><p>710 710</p><p>First results (Feb09-Jun09)DFT model:DFT model: Adsorption energies of all the HOR and ORR Adsorption energies of all the HOR and ORR intermediates on Pt(111) and Ptintermediates on Pt(111) and Pt33Ni(111)Ni(111)--skeleton surfaces.skeleton surfaces.</p><p>Experimental:Experimental: Definition of simplified real cycles and first Definition of simplified real cycles and first tests in singletests in single--cells and excells and ex--situ characterizations.situ characterizations.</p><p>Global Global mechanisticmechanisticmodelmodel</p><p>ComplementaryComplementarymodellingmodelling toolstools</p><p>Atomistic (kinetics)parameters</p><p>Micro-structural (transport)parameters</p><p>ExperimentalExperimental inin--situsitu/ex/ex--situ situ electrochemicalelectrochemical tests tests andand</p><p>micromicro--structuralstructuralcharacterizationscharacterizations</p><p>Durabilityprediction Coupled ageing mechanisms understanding</p><p> Operating strategies mitigating degradation</p><p>Global Global mechanisticmechanisticmodelmodel</p><p>ComplementaryComplementarymodellingmodelling toolstools</p><p>Atomistic (kinetics)parameters</p><p>Micro-structural (transport)parameters</p><p>ExperimentalExperimental inin--situsitu/ex/ex--situ situ electrochemicalelectrochemical tests tests andand</p><p>micromicro--structuralstructuralcharacterizationscharacterizations</p><p>Durabilityprediction Coupled ageing mechanisms understanding</p><p> Operating strategies mitigating degradation</p><p>Project structure: strong coupling between Project structure: strong coupling between targeted experiments and targeted experiments and multiscalemultiscale modelingmodeling</p><p>Project methodology for the MEA durability Project methodology for the MEA durabilit...</p></li></ul>

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