Multiple crystal phases of intermetallic tungsten borides and phase-dependent electrocatalytic property for hydrogen evolution

Abstract

Four stoichiometric W–B intermetallic phases, including W₂B, WB, WB₂ and WB₃, are synthesized, and their hydrogen-evolution electrocatalytic properties and electronic structures are investigated comparatively. The electrocatalytic activity for the hydrogen evolution reaction is found to first increase from W₂B to WB₂ and then decrease; and this activity trend can be rationalized based on their different degrees of hybridization between d orbitals of W and sp orbitals of B.