铂/聚邻甲基苯胺/碳材料掺杂碳糊电极对甲醇的催化氧化

以石墨和液体石蜡油为主要原料,分别制备了掺杂不同量多壁碳纳米管(MWCNT)、石墨烯(GRA)、电容活性炭(YEC)和电池活性炭(YBC)的多种碳糊底电极Y-CPE(Y代表各种掺杂碳材料,CPE代表纯碳糊电极).采用恒电位法在-0.10 V(vs.Ag/Ag Cl)电位下将铂电沉积到这些电极上.结果表明,当电池碳的含量为14%时,Pt/YBC-CPE(14%)复合电极对甲醇具有最好的电催化氧化活性.采用恒电位方法在0.85 V(vs.Ag/Ag Cl)电位下将聚邻甲基苯胺(POT)电聚合沉积到纯碳糊电极CPE和含有电池碳的YBC-CPE(14%)电极上,得到复合电极POT/CPE和POT/YBC-CPE(14%),再通过恒电位方法将铂电沉积到这2个复合电极上.扫描电镜(SEM)观察结果表明,在Pt/CPE,Pt/YBC-CPE(14%),Pt/POT(6.5 mC)/CPE和Pt/POT(6.5 mC)/YBC-CPE(14%)4个复合电极中,在Pt/POT/YBC-CPE(14%)复合电极上的铂粒子的尺寸最小,并且Pt/POT(6.5 mC)/YBC-CPE(14%)复合电极电催化氧化甲醇活性最高.在POT(6.5 mC)/CPE和POT(6.5 mC)/YBC-CPE(14%)上Pt纳米颗粒的电沉积过程是一个近似的3D成核过程.研究还发现,复合电极Pt/POT/CPE和Pt/POT/YBC-CPE电催化氧化甲醇的活性随POT膜厚度的增加先增大后减少,存在一个最佳的膜厚度.

Methanol Electrocatalytic Oxidation on Pt / Poly(o-toluidine) Film / Activated Carbon Doped Graphite Carbon Paste Electrode

Various liquid oil-bound carbon paste electrodes were prepared from the mixtures of graphite powders and paraffin( CPE), multi-walled carbon nanotubes and graphite powders and paraffin ( MWCNT-CPE), graphene and graphite powders and paraffin( GRA-CPE), activated capacitors carbon and graphite powders and paraffin(YEC-CPE), activated batteries carbon and graphite powders and paraffin(YBC-CPE), respectively. Poly(o-toluidine)(POT) film was prepared by constant potential deposition at 0. 85 V(vs. Ag |AgCl) in monomer solution at the surface of CPE and YBC-CPE(14%) (14% refers to the mass fraction of YBC in the carbon mixture materials) with various film growth charges. Platinum nanoparticles were success-fully electrodeposited on Y-CPE( Y refers to the various carbon materials mentioned above except graphite powders), POT/ CPE, POT/ YBC-CPE(14%) at a fixed potential of -0. 10 V(vs. Ag | AgCl) in 0. 5 mol/ L H2 SO4 solution containing 3.0 mmol/ L H2 PtCl6 . In order to learn about the instantaneous or progressive nucle-ation process of platinum on composite electrodes, non-dimensional plots of (I/ Im) 2 vs. t/ tm of the experimen-tal were compared with theory through the expressions. The morphologies of platinum nanoparticles were char-acterized by scanning electron microscopy(SEM). The SEM images reveal that the presence of YBC and POT influences the size of platinum nanoparticle. The electrocatalytic activities of as-formed Pt/ CPE, Pt/ POT/CPE, Pt/ YBC-CPE and Pt/ POT/ YBC-CPE(14%) towards the electrooxidation of methanol were evaluated by cyclic voltammetry ( CV). The experimental results indicate that compared with other POT/ Y-CPE, Pt/ POT/ YBC-CPE(14%) has the best electrocatalytic activity towards methanol oxidation in an acidic medium.