Study of the Kinetics of Hydrogen Evolution Reaction on Raney Nickel Composite‐Coated Electrode by AC Impedance Technique

Abstract

The hydrogen evolution reaction on the Raney nickel composite‐coated electrode is investigated in aqueous solution at 70°C by ac impedance technique. In case of the chemically activated electrode material, the easiest pathway for the hydrogen evolution reaction (HER) is the Volmer‐Tafel mechanism, and the controlling step is the Volmer reaction with a small contribution of the Heyrovsky reaction. The electrode material becomes more electrocatalytic towards the HER after an electrochemical activation. In this case, the easiest pathway for the HER is the Volmer‐Heyrovsky mechanism, both steps being rate‐controlling.