EIS analysis on the anodic dissolution kinetics of pure iron in a highly alkaline solution

The anodic dissolution kinetics of pure iron in a highly alkaline solution was systematically studied by EIS. A model based on its reaction mechanism was proposed, which can well explain the characteristics of EIS. From the model, it was found that the Fe(III) oxide covered on the iron surface was firstly electrochemically oxidized to an adsorbed Fe(V) intermediate, the latter then converted to the final Fe(VI) product and the initial Fe(III) reactant through a disproportionating reaction. The kinetic constants of each step as well as the covering densities of the Fe(III) reactant and the Fe(V) intermediate at different potentials were calculated from the EIS model.