Studies On Electrochemical Oscillations For Cathodic Reduction Of Several Oxysalts

Electrochemical oscillations, a spatiotemporal phenomenon under conditions of keeping far away from equilibrium, have aroused much interest of many researchers. Electrochemical oscillatory systems are suitable as model systems because they have several merits such as complex kinetic behaviors can be displayed by time series of potential or current with low noise and short period, and control as well as measurements of current and potential are straightforward and easy. In order to find more oscillators, Koper and our group advanced successively impedance-based and cyclic-voltammetry-based experimental criteria, respectively, and much practice shows that the latter is more effective, intuitive and less time-consuming than the former.By cyclic voltammetry, two types of electrochemical oscillations were found in the reduction of dichromate, permanganate in acid solution, and bromate in alkaline solution. The techniques of Electrochemical quartz crystal microbalance (EQCM), Raman and Infrared spectroscopy were used to study the mechanism.1. Two types of potential oscillations during dichromate reduction on gold electrode in sulfuric acid solutionTwo different types of potential oscillations have been identified for the first time during the dichromate reduction on a gold electrode in a dilute sulfuric acid. One occurs before hydrogen evolution due to the formation and dissolution of passivating films of low-valency chromium oxides, and the other arises accompanying periodic hydrogen evolution...