恒电流阶跃法研究金属络离子还原反应的机理

A STUDY OF ELBCTROCHRMICAL REDUCTION MECHANISMS OF METAL COMPLEX ION BY CONSTANT CURRENT CHRONOPOTENTIOMETRY

本文从理论上阐述了恒电流阶跃法,研竟金属络离子放电还原反应机理在金属—配位体—水系组成的电解质溶液中,若配位体浓度远大于金属离子总浓度,且恒定溶液离子强度和“主要存在形式”的金属络离子浓度,恒电流阶跃法则得电位波的过渡时间只与溶液中配位体浓度有关。由两者之间的定量关系,可确定在电极表面直接放电还原金属络离子和前置转化反应的具体式,由对应的电位—时间曲线方程可确定电极反应性质和有关电化学动力学参数。

The principles of studying electrochemical reduction mechanisms ofmetal complex ion by constant current chronopotentiometry have been exp-ounded in the paper. If the ligand concentration is far larger than the to-tal concentration of metal ion, the transition time measured by constantcurrent chronapotentiometry only depends upon the ligand concentrationswhen the ion intensity and the concentration of one main type of metalcomplex ion are constantant in electralytic solutions. The quantitative rel-ation between them can be used to determine mechanisms of electrode re-action and the potential-time curvilinear equations can be used to determi-ne some kinetic data of electrochemical reaction.