Hydrogen Induced Abrupt Structural Expansion at High Temperatures of a Ni₃₂Nb₂₈Zr₃₀Cu₁₀ Membrane for H₂ Purification

Ni-Nb-Zr amorphous membranes, prepared by melt-spinning, show great potential for replacing crystalline Pd-based materials in the field of hydrogen purification to an ultrapure grade (>99.999%). In this study, we investigate the temperature evolution of the structure of an amorphous ribbon with the composition Ni₃₂Nb₂₈Zr₃₀Cu₁₀ (expressed in atom %) by means of XRD and DTA measurements. An abrupt structural expansion is induced between 240 and 300 °C by hydrogenation. This structural modification deeply modifies the hydrogen sorption properties of the membrane, which indeed shows a strong reduction of the hydrogen capacity above 270 °C.