Logistic Modeling of Copper Oxidation in Alkaline Media Considering Solubility Gaps between the Solid Oxidation Products

A theoretical model is proposed to describe the essential features appearing in the voltammetry of copper electrodes in contact with aqueous alkaline media. The model is based on the introduction of miscibility gaps into a logistic formulation of the charge/potential relationship. This is directly inspired by ion-insertion electrochemistry and emphasizes the OH–-assisted nature of the involved oxidation processes. The model accounts for miscibility limits and refinements, accounting for deviations from reversibility, diffusive constraints, and nucleation rate effects can be added. Linear potential scan voltammetric parameters, in particular the large potential hiatus existing between anodic and cathodic peaks, can be satisfactorily reproduced with this model.