Mechanism and activity of the oxygen reduction reaction on WTe₂ transition metal dichalcogenide with Te vacancy

Abstract

WTe₂ transition metal dichalcogenide is a promising candidate for the cathode of proton-exchange membrane fuel cells. In this paper, we investigated the mechanism and activity of the oxygen reduction reaction on the monolayer of the WTe₂ transition metal dichalcogenide with Te vacancy denoted as WTe^d ₂. By using density functional theory calculations, we studied the reaction intermediates on the surface of WTe^d ₂. The Gibbs free energy was calculated to clarify the thermodynamic properties of the reaction. We discovered that the ORR mechanisms are more favorable outside than inside the vacancy. The ORR activity was found to be comparable to that of the well-known transition metal electro-catalysts.