Concepedia

Abstract

The electrochemical behavior of the , , and interfaces at different temperatures was investigated using potentiodynamic techiques, covering the potential range between the reaction and the reaction. Electrodes with different degrees of activation were employed. The surface electrooxidation is explained by a sequence of reactions involving oxo‐hydroxo species and electroformation. The activation effect, particularly noticed with at 25°C, is assigned to an accumulation of oxo‐hydroxo species on the electrode and the occurrence of proton transfer reactions. The activation effect is practically absent in the melt, but instead, it exhibits an aging of the electroformed oxygen‐containing species, which under a complete coverage probably entails an monolayer. Results with 96% correspond to an intermediate situation between and molten , depending on the temperature.