Hydrogen-storage properties of Mg-10Â wt.% (Fe2O3, Ni, MnO) alloy prepared by reactive mechanical grinding

The samples Mg-10 wt.% (Fe2O3, Ni, MnO) was prepared by mechanical grinding under H2 (reactive mechanical grinding) under the optimum conditions, studied previously, for the preparation of the sample Mg-10 wt.% Fe2O3 using purchased Fe2O3. The sample Mg-10 wt.% (Fe2O3, Ni, MnO) as milled absorbed 4.15 wt.% hydrogen at 593 K under 12 bar H2 for 60 min. Its activation was accomplished after two hydriding-dehydriding cycles. The activated sample absorbed 4.02 wt.% hydrogen at 593 K, 12 bar H2 for 60 min desorbed 3.03 wt.% hydrogen at 603 K, 1.0 bar H2. Hydrogen-storage capacity was 5.34 wt.% under 12 bar at 593 K (from P-C-T curve). The equilibrium plateau pressure is about 1.5 bar H2. Mg-10 wt.% (Fe2O3, Ni, MnO) has lower hydriding rate than Mg-10 wt.% Fe2O3 by spray conversion, but it has higher dehydriding rate than Mg-10 wt.% MnO and Mg-10 wt.% Fe2O3 by spray conversion.