Hydrogen-storage properties of Mg-oxide alloys prepared by reactive mechanical grinding

The samples Mg-10 wt.% M (M = Fe2O3 purchased, Fe2O3 by spray conversion, MnO purchased, and SiO2 by spray conversion) were prepared by mechanical grinding under H2 (reactive mechanical grinding) under the optimum conditions for the preparation of the sample Mg-10 wt.% Fe2O3 using purchased Fe2O3. The activated Mg-10 wt.% Fe2O3 by spray conversion has the highest hydriding rate (Ha = 5.55 wt.% at 593 K, 12 bar H2 for 60 min) of all the samples. The activated Mg-10 wt.% MnO has the highest dehydriding rate (Hd = 1.94 wt.% at 593 K, 1.0 bar H2 for 60 min). The equilibrium plateau pressure is about 1.5 bar H2. The effects of reactive mechanical grinding and hydriding-dehydriding cycling on the hydrogen properties of Mg were discussed.