Experimental and Theoretical Insights into the Potential of V₂O₃ Surface Coatings for Hydrogen Permeable Vanadium Membranes

A grand challenge of vanadium-based H₂ permeable membranes is the development of effective, cheap, and stable catalysts to facilitate H₂ dissociation and recombination. This work investigates a facile air treatment to form catalytically active vanadium oxide on the surfaces of dense vanadium foils. The treatment consisted of short air exposure followed by H₂ reduction at 823 K, which produced a well-faceted and nanocrystalline V₂O₃ layer on the foil surfaces. The resulting membranes displayed a stable H₂ permeability of 2 ± 0.25 × 10^–8 mol·m^–1·s^–1·Pa^–0.5, but transient declines in permeation were observed when operated at both elevated and reduced temperatures. DFT calculations revealed that V₂O₃ (0001) surfaces display barriers and adsorption energies for H₂ dissociation/recombination that are comparable to those of known H₂ activation catalysts. It was found that H₂ dissociation is expected to proceed spontaneously on metal-terminated V₂O₃, with recombinative-desorption anticipated as the rate limiting step