Effect of Ce-Ni alloy Addition on Hydrogen Desorption Temperature of Magnesium Hydride-Based Composite Produced by Mechanical Alloying

Abstract In this study, the composite materials with composition of MgH2-10 wt% (50Ce50Ni) (composite C5N5) and MgH2-10 wt% (25Ce75Ni) (composite C2N7) have been prepared by co-milling of MgH2 powder with Ce-Ni alloy produced by vacuum arc remelting. The effect of additive on MgH2 structure, i.e. crystallite size, lattice strain and particle size, and also hydrogen desorption properties of obtained composites were evaluated and compared with pure milled MgH2. It has been shown that the addition of Ce-Ni alloys to magnesium hydride leading to a reduction in the particle size from 1.3 m to 0.6 m for composite C5N5 and to 0.75 m to composite C2N7. As a consequence, the desorption temperature of mechanically activated MgH2 for 5 h has decreased from 340?C to 280?C for composite C5N5 and to 268?C for composite C2N7. Further improvement in the hydrogen desorption of composite C2N7 can be related to higher Ni value, which corresponded with calculated enthalpy results.