Mechanism of cadmium anodic oxidation in concentrated KOH solutions with trilon B additions

The results of chronoamperometric measurements performed on the rotating disc electrode of cadmium in 8.1N KOH solutions with the additions of 10,20,30,40 g/l trilon B, in 5 and 10N KOH solutions with the additions of 20 g/l trilon B have been used to show that anodic process in the range of potentials of active anodic cadmium oxidation is described by the regularities of mixed kinetics. Diffusion and kinetic constituents of the anodic current are determined. Electrochemical cadmium oxidation in alkali can be presented as a totality of two competing processes: anodic electrode dissolving with the formation of hydroxocadmate complexes, and the process of formation and accumulation of irreversibly adsorbing oxide foms on the surface which brings about electrode passivation. The introduction of trilon B addition into electrolyte has permitted to separate these processes due to the expansion of the range of active oxidation potentials to cathode side and increase of the first process rate. The heterogeneous chemical reaction of adsorbed oxide solution is the limiting stage of this process