Abstract

However, the hydrogenation and dehydrogenation kinetics of MgH2 is very slow, Mg with its low cost and ability to store a high hydrogen content (7.60 wt.%) is considered to be the most promising materials for solid-state hydrogen storage applications in light vehicles. The absorption and desorption kinetics of MgH2 powders can be improved by subjecting the powders to long-term of milling followed by mechanical milling with 3d transition metals and their alloys. Although there are many reported efforts performed to improve the hydrogenation/dehydrogenation properties of this binary system, there is still a space for new attempts that aims to find a suitable catalytic system(s) used to improve the absorption and desorption kinetics of this promising metal hydride system. The present study has been addressed in part to investigate the effect of new catalytic systems for improving the kinetics of hydrogenation and dehydrogenation properties for MgH2 system synthesized by reactive ball milling technique. In the present study, metallic glassy- and big cube- Zr2Ni powders were prepared by mechanical alloying and then individually doped (10 wt.%) to MgH2 powders, using high-energy ball milling. The results have shown that the sorption and desorption kinetics of the two MgH2 systems examined at 250 °C were significantly improved. This implied by the fast absorption and desorption processes taking place within very short time. Moreover, our new systems showed extraordinary cycle-life-time extended to 1240 h (2546 cycles) without serious degradations.

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