粗糙化银电极上3,4,5,6-四氯吡啶甲酸的电催化还原

Electrocatalytic reduction of 3,4,5,6-tetrachloropicolinic acid on roughened silver electrode

用电化学氧化还原法(ORC)制备了粗糙化银电极.采用原子力显微镜(AFM)对粗糙化银电极表面结构进行了表征,用循环伏安法和大幅度电势阶跃法研究了碱性水溶液中粗糙化银电极对3,4,5,6-四氯吡啶甲酸(3,4,5,6-TCP)的电催化还原特性.结果表明:用电化学氧化还原法(ORC)制备得到的粗糙化银电极表面交错分布了棉絮状微晶和圆柱状晶枝,对3,4,5,6-TCP脱氯反应显示了很高的电催化活性;该脱氯反应是受扩散控制的不可逆反应,求得传递系数α为1.51nα-1,扩散系数D为0.820×10-6(cm2.s-1).

Roughened silver electrodes were prepared by electrochemical oxidation-reduction （ORC）. The silver electrodes were characterized by atomic force microscopy （AFM）. The electrochemical characteristics of the roughened silver electrodes towards reduction of 3,4,5,6-tetrachloropicolinic acid in basic solution were investigated by chronoamperometry and cyclic vohammetry. Experimental results showed that the roughened silver electrode exhibited powerful electrocatalytic activity for the reduction of 3,4,5,6-tetrachloropicolinic acid, the dechlorinaton of 3, 4,5,6-tetrachloropicolinic acid on roughened silver electrode was irreversible process and the electrode reaction was controlled by diffusion. The diffusion coefficient D of 3,4,5,6-tetrachloropicolinic acid in basic solution was 0. 820 × 10^-6 （cm^2 · s^-1 ）, while the transfer coefficient α was 1.51na^-1.