Atomic-level prediction of V–Ni–Al, V–Ni–Co and V–Ni–Fe ternary alloys as highly selective hydrogen separation membranes

Abstract

VB-group-based ternary alloys membranes for hydrogen separation have attracted great attention because of their superiorities on selectivity and permeability of hydrogen. However, atomic-scale hydrogen separation properties of the ternary alloys are still not studied, further related study is critical for developing high-performance V–Ni-based alloys membranes. In this work, molecular dynamics (MD) and first-principles calculation are incorporated to predict performances of V–Ni–Al, V–Ni–Fe and V–Ni–Co ternary alloys for separation of H2 from N2, CO2, CO, CH4, H2O and H2S mixed gases. Based on calculations of adsorption properties, diffusion energy barrier, selectivity and charge density difference, it reveals that the alloys membranes show excellent permeance and selectivity for separation of hydrogen gas. In particular, V–Ni–Al membrane presents superior diffusion and permeability properties for hydrogen gas. Our calculations provide an insight into atomic-level mechanism of V–Ni–Al, V–Ni–Fe and V–Ni–Co alloys as high-performance hydrogen separation membranes.