Structure Sensitivity in Hydrogen Adsorption on Ni/NiO Interfaces for the Hydrogen Evolution Reaction
Feng Zhou, Guohua Tao
Abstract
Hydrogen adsorption on interfaces plays an indispensable role in catalytic processes such as the hydrogen evolution reaction. Despite extensive studies, the underlying mechanism of interfacial adsorption is not fully understood. Here, we performed the DFT calculations on the hydrogen adsorption on the metal surface near the Ni/NiO interface. The results reveal that the hydrogen adsorption is site-dependent, and the interfacial effect exhibits a strong dependence on the distance to the boundary. The electronic structure analysis suggests that both the ligand effect and charge transfer effect contribute to weakening the hydrogen adsorption near the Ni/NiO boundary. The incorporation of the d-band center shift and the oxidation state of the adsorption site as the effective descriptor is suggested to understand the underlying mechanism of surface adsorption. The descriptor seems to capture the structural sensitivity in hydrogen adsorption across a variety of interfacial models fairly well, and a nearly linear relationship is found between Δ G H and the descriptor.