Theoretical Study on Improving the Catalytic Activity of a Tungsten Carbide Surface for Hydrogen Evolution by Nonmetallic Doping

Tungsten carbide (WC) has received widespread attention as a new type of nonprecious metal catalyst for hydrogen evolution reaction (HER). However, it is still a challenge to improve the surface HER catalytic activity. In this work, the effects of different nonmetallic dopants on the catalytic activity and stabilities of WC (0001) surface for HER were studied by first principles methods. The effects of different types of non-metal (NM = B; N; O; P and S) and doping concentrations (n(i) = 25-100%) on HER catalytic activity and stability were investigated by calculating the Gibbs free energy of hydrogen adsorption ( increment G(H)) and substitution energy. It was found that the catalytic performance can be improved by doping O and P non-metallic elements. Especially, the increment G(H) with P doped is -0.04eV better than Pt (-0.085 eV), which is a potential ideal catalyst for HER. Furthermore, the electronic structure analysis was used to explore the origin of the regulation of doping on stability and catalytic activity. The results show that nonmetallic doping is an effective strategy to control the catalytic activity, which provides theoretical support for the future research of HER catalysts.