Hydrogen Permeation of Pd-Free V-Based Metallic Membranes for Hydrogen Separation and Purification

With the aim of replacing Pd coating layer currently used for the dissociation and recombination of hydrogen molecules, the performance of Nb and Ta thin layers as catalystforhydrogen permeationwas evaluated at 673 K. Although not as efficient as Pd, Nb and Ta coating layers can nevertheless provide a reasonable H(2) dissociation and recombination rates. Thereduced values of hydrogen permeabilityin comparison to that of Pd were explained by the reduced catalytic properties of Nb and Ta and the formation of hydrides on the surface.