硫酸溶液中重铬酸钾在金电极上还原过程中的两种电势振荡

首次报道稀硫酸溶液中重铬酸钾在金电极上还原时产生的两种不同类型的电势振荡．一类发生在析氢之前,涉及电极表面低价铬氧化物钝化膜的形成和溶解;另一类伴随周期性析氨,源自电化学反应与扩散-对流传质的耦合．更有意义的是,这两种类型的电化学振荡分别与循环伏安图中的两个交叉环相对应．

Two Types of Potential Oscillation During the Reduction of Dichromate on Gold Electrode in H2SO4 Solution

Two different types of potential oscillations have been identified for the first time during dichromate reduction on a gold electrode in a solution of dilute sulfuric acid. One occurs before hydrogen evolution due to the formation and dissolution of passivating films of low-valence chromium oxides, and the other generates, accompanying periodic hydrogen evolution, from the coupling of electrochemical reactions with diffusive and convective mass transport. More interestingly, these two types of oscillations correspond to two crossing loops in the cyclic voltammogram(CV).Such a relation of oscillations with crossed CVs will provide a new way to find electrochemical oscillatory systems systematically and rapidly.