摘要
Thepyrolyzedcarbonsupportedferrumpolypyrrole(Fe-N/C)catalystsaresynthesizedwithorwithoutselecteddopants,p-toluenesulfonicacid(TsOH),byafacilethermalannealingapproachatdesiredtemperatureforoptimizingtheiractivityfortheoxygenreductionreaction(ORR)inO2-saturated0.1mol/LKOHsolution.Theelectrochemicaltechniquessuchascyclicvoltammetry(CV)androtatingdiskelectrode(RDE)areemployedwiththeKoutecky-LevichtheorytoquantitativelyobtaintheORRkineticconstantsandthereactionmechanisms.ItisfoundthatcatalystsdopedwithTsOHshowsignificantlyimprovedORRactivityrelativetotheTsOH-freeone.TheaverageelectrontransfernumbersforthecatalyzedORRaredeterminedtobe3.899and3.098,respectively,forthecatalystswithandwithoutTsOH-doping.Theheat-treatmentisfoundtobeanecessarystepforcatalystactivityimprovement,andthecatalystpyrolyzedat600℃givesthebestORRactivity.Anonsetpotentialandthepotentialatthecurrentdensityof-1.5mA/cm2forTsOH-dopedcatalystafterpyrolysisare30mVand170mV,whicharemorepositivethanthosewithoutpyrolized.Furthermore,thecatalystdopedwithTsOHshowshighertolerancetomethanolcomparedwithcommercialPt/Ccatalystin0.1mol/LKOH.TounderstandthisTsOHdopingandpyrolyzedeffect,X-raydiffraction(XRD),scanningelectronmicroscope(SEM)andX-rayphotoelectronspectroscopy(XPS)areusedtocharacterizethesecatalystsintermsoftheirstructureandcomposition.XPSresultsindicatethatthepyrrolic-Ngroupsarethemostactivesites,afindingthatissupportedbythecorrespondencebetweenchangesinpyridinic-NcontentandORRactivitythatoccurwithchangingtemperature.SulfurspeciesarealsostructurallyboundtocarbonintheformsofC–Sn–C,anadditionalbeneficialfactorfortheORR.
出版日期
2014年04月14日（中国期刊网平台首次上网日期，不代表论文的发表时间）
