Magnesium and its hydride MgH 2 are widely regarded as promising candidates for hydrogen storage materials due to its benefits of high gravimetric and volumetric capacity, excellent reversibility, abundance in the earth and a low cost. Much attention has been paid to improve its absorption/desorption kinetics, trying to make it useful for practical applications. To make composite of MgH 2 with other hydrogen storage compounds is an effective method to improve the hydrogen storage properties. In this study nanocomposite of MgH 2 with ZrCrCu alloy was prepared using high energy ball-milling for 5 h under Ar atmosphere. Microstructure and morphology of the composites were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM). XRD patterns show that no alloy formation between MgH 2 and elements of the alloys takes place during milling. Different morphology of the powders as-milled and after cycling was observed by SEM. Pressure-composition isotherms of these composites have been obtained in the pressure range 0.1-10 bar at 275 and 300 °C. The absorption/desorption kinetics data have been analyzed using pressure 0.1-5.0 bar at 275 and 300 °C to understand the mechanism of the hydriding/dehydriding reaction processes. A comparison of these results has been attempted with our previous published results of MgH 2-10 wt%ZrCrNi in order to find the better composite for storage applications. It is observed by DSC curves that the onset temperature of hydrogen desorption is decreased for MgH 2-10%ZrCrNi in comparison to MgH 2 which further decreased for MgH 2-10%ZrCrCu. However, little loss in hydrogen absorption/desorption capacity is also observed for ZrCrCu composite in comparison to that of ZrCrNi composite. © Springer Science+Business Media B.V. 2010.

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