A Model for the Anodic Dissolution of Zinc in Alkaline Electrolyte: Kinetics of Initial Dissolution

We propose a three‐step mechanism to describe the kinetics of the initial dissolution of zinc in alkaline electrolyte. The rate‐determining step is postulated to be a reversible reaction where a monovalent zinc hydroxide is converted to a soluble zincate. The surface reactions are assumed to occur on activated sites, where Langmuir adsorption is assumed. The reaction scheme is shown to be consistent with experimental quantities such as Tafel slope and reaction order for data obtained near room temperature in approximately 1N hydroxide electrolyte. The thermodynamic consistency of each elementary step is demonstrated from an analysis of available free energy data.