导电聚吡咯膜电极上的电催化作用的研究(Ⅰ)——抗坏血酸的电催化氧化

Electrocatalysis of Electrodes Coated with Conducting Polypyrrole Films——Electrocatalytic Oxidation of Ascorbic Acid

研究导电聚吡咯(PP)膜电极在酸性水溶液中对抗坏血酸(AH_2)的电催化氧化反应,电化学循环伏安结果表明AH_2在PP/Pt电极上的氧化电位比在Pt电极上的氧化电位负移200～300mV。实验分析了反应的Tafel曲线并讨论了可能的反应机理。实验还用XPS、ESR研究手段,探讨了AH_2与PP之间的相互作用,认为整个电催化过程可能是电子传递催化作用和化学催化作用的偶联。

Electrocatalytic oxidation of ascorbic acid(AH2) in acidic solutions was studied at electrodes coated with conducting polypyrrole(PP) films. Shifts of 200-300mV for the oxidation potential of AH2 at the polymer-coated electrodes were observed by cyclic voltammetry. Through measurements of Tafel plots, the mechanism of electrocatalytic oxidation of AH2 was discussed. With the help of XPS and in-situ ESR spectrum, interactions between electrochemically oxidized PP and AH2 surface species were also discussed.A coupling of electron-transfer-mediated catalysis and chemical catalysis on PP was believed.