Substantial enhancement of hydrogen permeability of Mo2C/V composite membranes by ion beam sputtering

Abstract

Ion beam sputtering (IBS) was used to deposit Mo 2 C catalytic layers on vanadium (V) foils and to prepare Mo 2 C/V composite membranes for hydrogen separation and purification. It is found that the sputtering temperature during IBS largely affects the structure and catalytic activity of the as-deposited Mo 2 C films. A high sputtering temperature facilitates the growth of cubic Mo 2 C along the catalytically dominant crystal plane, which substantially enhances the hydrogen permeability of Mo 2 C/V. Typically, the Mo 2 C/V membranes prepared by IBS at a sputtering temperature of 600 °C exhibit a significantly high hydrogen permeability of ∼ 6.7 × 10 −8 mol H 2 m −1 s −1 Pa −0.5 at a hydrogen permeation temperature of 600 °C. This is 2.4 times that of Pd and 2.0 times that of Mo 2 C/V membranes prepared by conventional magnetron sputtering. The present work demonstrates that IBS is a promising technique to prepare highly permeable and cost-effective Mo 2 C/V membranes for high temperature hydrogen separation. • Ion beam sputtering is a potential method to prepare Mo 2 C/V for H 2 separation. • The sputtering temperatures largely affect the microstructures of Mo 2 C films. • The cubic Mo 2 C by ion beam sputtering exhibits a preferred growth of (220) plane. • Enhancement of catalytic activity of Mo 2 C leads to high H 2 permeability of Mo 2 C/V. • The highest H 2 permeability of Mo 2 C/V membranes is ∼2.4 times that of pure Pd.