Introduction: The evolution of hydrogen gas at the cathode is one of the reactions most frequently occurring in industrial cells. Besides the obvious case of water electrolyzers, hydrogen evolution occurs at the cathode of chlor-alkali and chlorate cells, which are among the most intensive electrochemical processes. On the other hand, hydrogen liberation is the cathodic process in cells containing aqueous solutions or protonated solvents where the wanted reaction takes place at the anode.
