不饱和有机酸在Pt-Rh合金电极上的吸附动力学

采用快速动电位扫描方法 ,系统地研究了吸附时间、溶液浓度、温度、吸附电位等因素对在不同组成的Pt-Rh电极上不饱和有机酸吸附过程的影响 .研究结果表明 ,在中等表面覆盖率下 ,所研究的不饱和有机酸在Pt-Rh合金电极上吸附速率都遵循Rogynski-Zilidowicz方程 ,Pt电极上吸附速率最大 ,从Pt电极向Rh电极过渡中 ,吸附速率下降 2 0～ 30倍 .温度升高吸附速率加快 .丙烯酸在Pt-Rh电极表面的吸附速率比其他不饱和有机酸高 ,并按丙烯酸 >丁烯酸 >顺丁烯二酸顺序递减

ADSORPTION KINETICS OF SOME UNSATURATED ALIPHATIC ACIDS ON Pt-Rh ALLOY ELECTRODES

On Pt-Rh alloy electrodes, the effect of some operational parameters on the adsorption process of several unsaturated aliphatic acids was respectively examined by fast cathodically potentiodynamic polarization. As the experimental results shown, the adsorption rates of acrylic acid , crotonic acid, and maleic acid, obey Rogynski-Zilidowicz equation always in the middle coverage .Comparatively, the maximal values are determined on the pure Pt-electrode, and as the electrode binary composition is varied successively from the pure Pt to Rh , the adsorption rates for these acids are generally decreased, even by 20～30 times. Among the three unsaturated aliphatic acids, acrylic acid is most advantageously adsorbed on the electrode surfaces. The adsorption activity order is acrylic acid ＞crotonic acid＞maleic acid.