Non-Noble Intertransition Binary Metal Alloy Electrocatalyst for Hydrogen Oxidation and Hydrogen Evolution

Abstract

Metastable and amorphous intertransition metal alloys of CuW are shown to catalyze both the hydrogen evolution reaction (HER) and the hydrogen oxidation reaction (HOR). The constituent metals exhibit poor activity. The results are consistent with ab initio calculations predicting HER activity for Cu overlayers on W and with the observed changes of the density of states (DOS) at the Fermi level associated with CuW alloy formation. Two maxima in the HER activity are observed as a function of composition corresponding a bulk metastable phase at 80 at % Cu and a second at 50 at % Cu. The alloy at 50 at % also corresponds to a maximum in the HOR activity, whereas the phase at 80 at % Cu is not HOR active. The latter phase is shown to be oxygen-covered at the HOR potential, explaining its inactivity. These results highlight the possibilities of developing non-noble metal alloy catalysts for hydrogen fuel cells.