Bimetallic Catalyst Effect on the Sorption Properties of Nanocrystalline MgH<sub>2</sub> Hydride

Abstract

In this work, we have investigated the hydriding/dehydriding properties and the effect of prolonged cycling done under pure hydrogen on the performance of nanostructured Mg-V-Ti composite synthesised by ball milling. The hydrogen charge and discharge characteristics of the nanocomposite hydride has been tested at 300°C using up to 1000 cycles. The comparison of the hydriding/dehydriding kinetics and the pressure-concentration-isotherms curves, measured before and after 1000 cycles, reveals no significant change in the kinetics and thermodynamic properties of the MgH 2 -V-Ti composite. However, a clear improvement in the cyclable hydrogen capacity was observed. SEM, X-ray and BET specific surface area characterisations reveal that the nanocrystalline Mg based composite exhibits an improved decrepitation resistance upon cycling.