Catalytic effects of V and V2O5 on hydrogen storage property of Mg17Al12 alloy

A Mg17Al12 alloy was synthesized via sintering, and the catalytic effects of V and V2O5 on the hydrogen (H2)-storage properties of this alloy were investigated. The results revealed that the hydrogenation/dehydrogenation temperature of Mg17Al12 decreased markedly and the reversible hydrogen storage properties improved with the addition of V or V2O5. For example, at 250 °C, the Mg17Al12 alloy underwent hydrogenation only and a hydrogen absorption capacity of 2.22 wt.% was realized. However, with the addition of V and V2O5, (i) reversible hydrogen absorption/desorption occurred, (ii) the hydrogen absorption capacity increased to 2.95 wt.% and 3.35 wt.%, and (iii) the hydrogenation/dehydrogenation enthalpy of the Mg17Al12alloy decreased from 65.7/83.1 kJ·mol−1 to 62.6/69.3 kJ·mol−1 and 59.9/68.1 kJ·mol−1, respectively.