Density functional theory study of H atom adsorption and H-induced segregation in Pd/V surfaces

Abstract

For hydrogen (H) storage and permeation applications, palladium/vanadium (Pd/V) membranes are of interest due to the ability of Pd to dissociate hydrogen molecule (H₂) and the high H permeability of V. However, previous studies observed that Pd/V suffers from atom interdiffusion when H is present in the surface. This study aims to investigate H adsorption on Pd/V surfaces by conducting density functional theory (DFT)-based calculations. Specifically, the energetics and charge density distributions of the systems are examined to determine the tendency of V atom segregation with and without H. We found that there is a tendency for interdiffusion when H is adsorbed on the Pd/V surface, and this is due to the stronger interaction of H with V atoms than with Pd atoms. Molybdenum (Mo) is then employed as a diffusion barrier layer (DBL) to address the interdiffusion phenomenon. The results suggest that Pd/Mo/V has a lesser interdiffusion tendency than pure Pd/V. Our results can contribute to understanding Pd/V-based systems and their interaction with H.