Dehydrogenation and hydrogenation characteristics of mechanically alloyed Mg-11 at.% In-1 at.% Fe alloy

The ionic bonding of MgH 2 must be made weaker in order to improve its dehydrogenation performance. Alloying of Mg with In, which has a larger electronegativity than Mg and is soluble to Mg, has a possibility to improve the dehydrogenation performance by weakening the ionic bonding of the hydride. A Mg–In–Fe alloy was, therefore, made by mechanical alloying and its behavior of dehydrogenation and hydrogenation was examined. Fe was added to expect its catalytic effect on hydrogen molecule dissociation. As a result, the mechanically alloyed Mg–In–Fe alloy powder showed better dehydrogenation and hydrogenation performance than a pure Mg powder made by thermal decomposition of a commercial MgH 2 powder. Activation energy of both dehydrogenation and hydrogenation reactions of Mg–In–Fe alloy powder decreased as compared with the pure Mg powder.