CONSIDERATIONS OF ADSORBED IONIC INTERMEDIATES ON THE AgO/Ag2O ELECTRODE IN AQUEOUS ALKALINE SOLUTION

Abstract

An experimental study of the kinetics for the electrochemical formation of AgO from Ag2O in aqueous alkaline solutions was reported in an earlier paper (1). The proposed mechanism for the rate-determining step was suggested to be the transfer of oxide ions across the mixed oxide interface. Further theoretical possibilities under Langmuir and Temkin conditions of surface coverages are considered here in the light of the previously obtained experimental data. In particular we examine the possibilities of the rate-determining step involving adsorbed ionic intermediates on the AgO/Ag2O electrode at the oxide/electrolyte interface. For the Temkin conditions, the intrinsic and induced heterogeneity models of Conway and his co-workers have been applied to our calculation of Tafel slopes. None of the mechanisms at the oxide/electrolyte interface were found to be rate-controlling.