Hydrogen-storage properties of Mg–10 wt.% (Fe 2O 3, Ni, MnO) alloy prepared by reactive mechanical grinding

Abstract

The samples Mg–10 wt.% (Fe 2O 3, Ni, MnO) was prepared by mechanical grinding under H 2 (reactive mechanical grinding) under the optimum conditions, studied previously, for the preparation of the sample Mg–10 wt.% Fe 2O 3 using purchased Fe 2O 3. The sample Mg–10 wt.% (Fe 2O 3, Ni, MnO) as milled absorbed 4.15 wt.% hydrogen at 593 K under 12 bar H 2 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 H 2 for 60 min desorbed 3.03 wt.% hydrogen at 603 K, 1.0 bar H 2. 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 H 2. Mg–10 wt.% (Fe 2O 3, Ni, MnO) has lower hydriding rate than Mg–10 wt.% Fe 2O 3 by spray conversion, but it has higher dehydriding rate than Mg–10 wt.% MnO and Mg–10 wt.% Fe 2O 3 by spray conversion.