Various forms of adsorbed hydrogen and their role in the hydrogen evolution reaction and hydrogenation of metallic phases in electrolyte solutions

Literature data have been considered and generalized which indicate the existence of several forms of adsorbed hydrogen on Fe, Pt, Pd, Ir, and Rh, including two oversurface and one subsurface species, whose properties differ substantially. It has been shown that, from the viewpoint of the existence of such forms of H ads and their mutual transitions into one another, a whole number of experimental data on corrosion and metal hydrogenation in electrolytic solutions can be interpreted satisfactorily.