Reaction of hydrogen evolution on Co−Mo (W) and Ni−Re electrolytic alloys in alkaline media

Resumo

The mathematical processing of experimental data is performed for the hydrogen evolution reaction (HER) in alkaline media on Co−Mo and Ni−Re cathodes obtained by electrodeposition. It is shown that it is necessary to take into account the possibility of occurrence of the stages of discharge (Volmer), electrochemical desorption (Heyrovský), and recombination of adsorbed hydrogen atoms (Tafel) in HER description on Co−Mo electrodes. Hydrogen evolution on Ni−Re cathodes is well modeled under the assumption of the Volmer–Heyrovský route (discharge and the following electrochemical desorption), but the contribution of diffusion of H_at into the cathode material is significant in the range of high cathodic current densities.