Hydrogen Overpotential and the Thermionic Work Function

Abstract

EXTENSIVE recent work1,2 on the hydrogen overpotentials at a large number of metal electrodes in aqueous solution allows a re-evaluation (see ref. 3) to be made of the relation between the hydrogen overpotential at various cathodes and the position of the cathode material in the periodic table. In the accompanying graph, the available values1,2 for the hydrogen overpotential at the intermediate current density of 10â3 amp./sq. cm. at various cathode materials, the surfaces of which have been prepared in approximately the same way, are shown in relation to the atomic number of the metals concerned, from which a periodic variation may clearly be discerned.