研究生英语文献汇报PPT.ppt

研究生英语文献汇报PPT.ppt

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1,PaperReview,李俊乾化学工程（专）14102932,SynthesisofbimetallicPt/Pdnano-tubesandtheirenhancedcatalyticactivityinmethanolelectro-oxidation（双金属铂/钯纳米管的合成和其在甲醇电氧化增强的催化活性）,2,Literaturesource,3,Contents,Introduction,1,2,Experimentalsection,1,Conclusions,2,3,4,Resultsanddiscussion,4,1.Introduction,Theshortageoftraditionalenergyresourcesandseriousenvironmentalpollutionduetocombustionemissionshaveresultedinanumberofscientificstudiesonthedevelopmentofsustainableandcleanenergy,includingfuelcells.,5,1.Introduction,Methanoloxidationinadirectmethanolfuelcell（DMFC）cangenerateelectrochemicalenergy.,DMFCSworkingprinciple:

Anode：

CH3OH+H2OCO2+6H+6e-0=0.046VCathode：

3/2O2+6H+6e-3H2O0=1.229V,CH3OH+3/2O2CO2+2H2O,E0=1.183V,Thisoxidationusuallyneedsacatalysttolowerthereactionbarriertomaketheprocessefficient.Sofar,platinum（Pt）isthemostefficientcatalystinthefield.ScarcityofPt,whichcausesitshighcost,inevitablyimpedestheactivedevelopmentofbothscientificresearchandpracticalutilization.Theutilizationofsingle-componentPtinDMFCssuffersfromseriouscarbonmonoxide（CO）poisoning.CO,oneofthemainintermediatemolecules,caneasilystainPtatoms,whichdeterioratestheircatalyticactivity.,6,Thearticlethought：

Inthisstudy,weachievedhighercatalyticactivityformethanoloxidationusingtheperpendicularbimetallicPt/PdNTarrayasacatalyst.TheinvestigationofthecatalyticpropertiesofbimetallicmaterialspavesawaytosubstitutingexpensivePtwithcost-competitivematerialsinthefuture.,7,Experimentalsection,2,8,2.Experimentalsection,5mMPdCl2,5mMH2PtCl6,40mMHCl,usedfordeposition,ThelengthsoftheNTscanbecontrolledbyusing0.3to2C.,AAO,avertically-alignedbimetallicPt/Pdnanotubearray,Scheme1Schematicdrawingoftheiondistributioninaporousaluminanano-template.DashedlinesshowtheelectricaldoublelayeroftheclassicalGouyChapmanSternsmodelbetween（b）diffusionlayerand（c）bulklayerregionsinananochannel.Region（a）depictsacompactlayer.,9,2,3,Resultsanddiscussion,10,3.Resultsanddiscussion,TheaverageouterdiameterandwallthicknessofthePt/PdNTsweremeasuredas217（39nm）and37（12nm）,respectively.AsshownintheSEMimages,theresultingmorphologyofthenanostructureswasquitehomogeneousoveralargeareaofthesample.,SynthesisofbimetallicPt/Pdnano-tubesandmorphologyanalysis,11,3.Resultsanddiscussion,AsthePt/Pdratioincreased（i.e.,theproportionofPt4+increased）,thenanostructuresbecamerodshapes.,AsthePt/Pdratiodecreased（i.e.,theconcentrationofPd2+increased）,thenanostructuresgraduallystartedtoshowanopennano-tubular（ONT）shape.,12,3.Resultsanddiscussion,When5mMPdand5mMPtprecursorionswereintheplatingsolution,Pt49/Pd51NTscouldbeprepared,Aplotofatomic%ofPtinPt/Pdbimetallicnanostructuresvs.amountofPtsource,13,3.Resultsanddiscussion,（A）TEMimageofPt/PdNTswith1C（2.40.4mm）showsthetotallytubularstructurefrombottomtotop.（B）TEMimageofaPt/PdNTandline-scanningprofilesintheradialdirection,indicatingPt（redtrace）andPd（greentrace）distributions.Thecorrespondingelementalmappingimagesareshownfor（C）Ptand（D）Pd.,14,3.Resultsanddiscussion,FE-SEMimages（BSEmode）ofthePt/PdNTs.ThelengthsofthePt49/Pd51NTsweretunedbyusing（A）0.3C,（B）1Cand（C）2C.（D）ThePt/PdNTshaveaveragelengthsfrom1.10.1mmto4.90.9mm.,15,3.Resultsanddiscussion,返回,Electro-catalyticproperties,（A）Cyclicvoltammograms（CVs）ofPtand/orPdnanostructureswithsamelengths（ca.2.4mm）in0.5MH2SO4solutionatroomtemperature.,AsshowninFig.A,thevalueofthesurfacechargeofthePt/PdNTcatalystswasfoundtobe1.7timeslargerthanthatofthePt/PdNRs.,16,3.Resultsanddiscussion,（B）AnodicstripingofCOoxidationin0.5MH2SO4aqueoussolutionfordifferentcatalysts（onlytheoxidativeCOremovalregionisshown）.,TheobservedpeakintensityofCOoxidationonthePt/PdNRswastwotimeshigherthanthatofthepurePtandPdNRs.Interestingly,theonsetpotentialofCOoxidationforthePt/Pdbimetallicnanostructures（0.61V）appearedatalowerpotentialcomparedtothepurePtNRs（0.69V）andthepurePdNRs（0.79V）.,17,3.Resultsanddiscussion,（C）Cyclicvoltammogramsofmethanoloxidationusingdifferentcatalysts.TheinsetimageshowsthemagnifiedonsetpotentialregionoftheCVs.,TheJf/JbratiosofthePt/PdNTsandPtNRsweredeterminedtobe1.6and1.2,respectively.,TheVonsetwasfoundtobeintheorder:

Pt/PdNTs（0.42V）Pt/PdNRs（0.44V）PtNRs（0.49V）,18,3.Resultsanddiscussion,（D）Comparisonofchronoamperogramsofmethanoloxidationfordifferentcatalystsat0.4V（vs.Ag/AgCl）.Electrolyteformethanoloxidation:

0.5MH2SO4and0.2MCH3OHsolutionatroomtemperature.Scanrate:

50mVs-1.,WefoundthatPt/PdNTsshowedthehighestcurrentdensitycomparedtoothernanostructures.,19,Conclusions,4,20,4.conclusions,1、WedemonstratedafacileroutetosynthesizehighlyorderedPt/Pdbimetallicnano-tubeelectrodesbasedonanAAOtemplate-directedelectrochemicalmethod.,2、TheperpendicularPt/Pdbimetallicnano-tubespresentedinthismanuscriptarepotentiallyusefulasenhancedelectro-catalystsinmethanolorothertypesoffuelcell.,21,Thankyouforyourattention!