杂多酸修饰多晶铂电极的制备及其电催化性能的研究

Preparation and electrocatalytic performance of heteropolyacid modified platinum electrode

为了改善铂基催化剂氧化甲醇的催化活性,首先通过循环伏安扫描制备了硅钨酸、磷钨酸、磷钼酸三种杂多酸修饰铂电极,通过研究铂电极修饰前后在硫酸底液中的循环伏安行为可知,尽管杂多酸具有较大的分子构型,但仍能在铂电极上吸附.另外通过循环伏安曲线研究了杂多酸修饰铂电极对甲醇氧化的电催化作用及抗一氧化碳毒化作用.测试结果表明:铂电极经杂多酸修饰后,能够大大提高其对甲醇氧化反应的催化活性以及抗一氧化碳毒化作用.并且三种杂多酸修饰铂电极中,磷钼酸修饰铂电极的催化活性最高,抗毒化作用最强.

In order to improve the electrocatalytic activity of platinum based catalyst to methanol oxidation, three heteropolyacids including phosphotungstic acid, phosphomolybdic acid and silicatungstic acid modified platinum electrodes were prepared by cyclic voltammetry scanning. The cyclic voltammetry curves of the heteropolyacids modified and unmodified platinum electrodes show that all three heteropolyacids can adsorb on platinum to form modified electrodes although they have big molecule structure. Meanwhile the electrocatalytic activity to methanol oxidation and anti -poison effect to mid -product of the heteropolyacids modified platinum electrodes are studied by cyclic voltammetry scanning. The results show that the electrocatalytic activity to methanol oxidation and anti -poison effect to carbon monoxide of platinum electrode can be improved by modification of heteropolyacids. Among three kinds of heteropolyacids modified platinum electrodes, the phosphomolybdic acid modified platinum electrode has the highest electrocatalytic activity and the strongest anti -poison effect.