• Transactions of the Korean hydrogen and new energy society
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• v.14 no.4
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• pp.321-326
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• 2003

We tried to improve the $H_2$-sorption properties of Mg by mechanical grinding under $H_2$ (reactive grinding) with CoO. The sample Mg+10wt.%CoO as prepared absorbs 1.25wt.% hydrogen and the activated sample absorbs 2.39wt.% hydrogen for 60min at 598K, $11.2barH_2$. The reactive grinding of Mg with CoO increases the $H_2$-sorption rates by facilitating nueleation(by creating defects on the surface of the Mg particles and by the additive), by making cracks on the surface of Mg particles and reducing the particle size of Mg and thus by shortening the diffusion distances of hydrogen atoms. Hydriding-dehydriding cycling increases the $H_2$-sorption rates by making cracks on the surface of Mg particles and reducing the particle size of Mg.