在聚邻甲苯胺 (POT)膜修饰电极上用电化学法沉积Pt微粒 ,由SEM与XRD表征其表面形态与晶面取向 ,同时研究异丙醇在金属化POT膜电极上的氧化行为 .结果表明 ,Pt在POT膜上的沉积呈现晶面择优取向的现象 ,况且POT质子掺杂后 ,由于电化学活性增强 ,影响了沉积铂微粒的尺寸和粒径分布 .异丙醇的电氧化可发生在POT的电化学活性区 ,当电位大于 0 .70V(SCE)时 ,POT不再呈氧化还原活性 ,异丙醇的电氧化主要在铂微粒上进行 .聚合物不仅作为铂微粒的载体而且自身参加反应 ,这种微异相催化体系需用新的模型描述
The platinum particles were electrodeposited on poly(o_toluidide),POT,modified electrode,and the surface configuration and crystal orientation of Pt particles were investigated by SEM and XRD.At the same time the oxidation of isopropanol on platinized POT modified electrode was studied.The results indicate that Pt particles deposite towards preferred_orientation;moreover the increase in polymer electroactivity due to proton doping affects the dimension and graininess of deposited Pt particles.At the metallized polymer electrode the oxidation of isopropanol can occur in POT electroactive potential region,however at the more positive than 0.70 V (SCE) potential where POT loses redox activity the electro_oxidation mainly occurrs on Pt particles.It follows that the polymer not only behaves as the support of Pt particles but also participates in the reaction. Such a “microheterogeneous catalysis system" needs to be described by a new model.
[1] XuJJ ,ZhouDM ,ChenHY .Amperometricdeterminationofascorbicacidatanovel“self_doped”polyanilinemodifiedmicroelectrode[J].FreseniusJ.Anal.Chem .,1998,36 2 (2 ) :2 34～ 2 38.
[2 ] StrehlitzB ,GrundigB ,KapinkcH .Sensorforamperometricdeterminationofammoniaandammonia_formingenzymereactions[J].AnalyticalChimicaActa .,2 0 0 0 ,4 0 3(1_2 ) :11～ 2 3.
[3] HoldcroftS ,FuntBL .Preparationandelectrocatalyticpropertiesofconductingfilmsofpolypyrrolecontainingplatinummicroparticulates[J].J .Electroanal.Chem .,1988,2 4 0 :89～ 10 3.
[4 ] VorkFTA ,BarendrechE .Thereductionofdioxygenatpolypyrrole_modifiedelectrodeswithincorporatedPtparticles[J].Electrochim .Acta .,1990 ,35:135～ 139.
[5] GholamianM ,ContractorAQ .Oxidationofformicacidatplatinummicroparticlesdispersedinapolyanilinematrix[J].J.Electroanal.Chem .,1990 ,2 89:6 9～ 83.
[6 ] BoseCSC ,RajeshwarK .Efficientelectrocatalystassembliesforprotonandoxygenreduction :theelectrosyn thesisandcharacterizationofpolypyrrolefilmscontainingnanodispersedplatinum particles[J].J .Electroanal.Chem .,1992 ,333:2 35～ 2 56 .
[7] YamatoH ,KoshibaT ,OhwaM ,etal.Anewmethodfordispersingpalladiummicroparticlesinconductingpolymerfilmsanditsapplicationtobiosensors[J].Synth .Met .,1997,87,2 31～ 2 36 .
[8] SumodjoPTA ,daSilvaEJ ,RabockaiT .Electrosorptionofhydroxylatedcompoumds:acomparativestudyofmoleculeswiththreecarbonatoms[J].JElectroanal.Chem .,1989,2 71:30 5～ 317.
[9] SunSG ,LinY .KineticaspectsofoxidationofisopropanolonPtelectrodesinvestigatedbyinsitutime_re solvedFTIRspectroscopy[J].J .Electroanal.Chem .,1994 ,375(1_2 ) :4 0 1～ 4 0 4 .
[10 ] PastorE ,GonzalezS ,ArviaAJ .ElectroreactivityofisopropanolonplatinuminacidsstudiedbyDEMSandFTIRS[J].J.Electroanal.Chem .,1995,395:2 33～ 2 4 2 .
[11] SunSG ,LinY .KineticsofisopropanoloxidationonPt(111) ,Pt(110 ) ,Pt(10 0 ) ,Pt(6 10 )andPt(2 11)sin glecrystalelectrodes_studiesofinsitutime_resolvedFTIRspectroscopy[J].ElectrochimicaActa ,1998,4 4 (6_7) ,1153～ 116 2 .
[12 ] AdamskiA ,SojkaZ ,DyrekK ,etal.Surfaceheterogebeityofzirconia_supportedV2 O5catalysts .Thelinkbe tweenstructureandcatalyticpropertiesinoxidativedehydrogenationofpropane[J].Langmuir,1999,15(18) :5733～ 574 1.
[13] BondGC .Preparationandpropertiesofvanadia/titaniamonolayercatalyst[J].AppliedCatalysisA_Gener al.,1997,157(1_2 ) :91～ 10 3.
[14] Dailizong ,Chemicalsynthesisandphysical_chemicalpropertiesofsolublering_substitutedpolyaniline[D].Xi amen :XiamenUniversity ,1999.
[15] FujitaI ,IshigushiM ,ShiotaH ,etal.SpectroscopicstudyofpolytoluidinesintheUV_visibleandIRregions[J].J.Appl.PolymerSci.,1992 ,4 4 ,987～ 992 .
[16 ] AndradeEM ,MolinaFV ,FioritML ,etal.IRresponseofpoly(o_toluidine) :Spectralmodificationsuponredoxstatechange[J].J.Electroanal.Chem .,1996 ,4 19:15～ 2 1
