Catalytic effects of metal oxide on hydrogen absorption of magnesium metal hydride

The composite metal hydride MgH2–MexOy powder was synthesized by high energy ball milling (MexOy = V2O5, Cr2O3, Al2O3, Fe2O3). The hydrogen absorption kinetics of composite metal hydride was determined by automated PCT measurements. The poor kinetics of MgH2 were greatly improved with an addition of oxide. In absorption, the catalytic effects of Al2O3 and Cr2O3 were remarkable at 300 °C with hydrogen capacity up to 4.09 and 4.02 wt%. At 250 and 200 °C, V2O5 showed that the fastest kinetics and hydrogen absorption capacities up to 3.2 and 2.25 wt%.