研究生英语文献汇报PPT.ppt

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 DMFC Sworkingprinciple Anode CH3OH H2O CO2 6H 6e 0 0 046VCathode 3 2O2 6H 6e 3H2O 0 1 229V CH3OH 3 2O2 CO2 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 DashedlinesshowtheelectricaldoublelayeroftheclassicalGouy Chapman Stern smodelbetween 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 1 0 1mmto4 9 0 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