Comparative investigations on the hydrogenation characteristics and hydrogen storage kinetics of melt-spun Mg10NiR (R = La, Nd and Sm) alloys

The hydrogenation characteristics and hydrogen storage kinetics of the melt-spun Mg10NiR (R = La, Nd and Sm) alloys have been studied comparatively. It is found that the Mg10NiNd and Mg10NiSm alloys are in amorphous state but the Mg10NiLa alloy is composed of an amorphous phase and minor crystalline La2Mg17 after melt-spinning. The alloys can be hydrogenated into MgH2, Mg2NiH4 and a rare earth metal hydride RHx. The rare earth metal hydride and Mg2NiH4 synergistically provide a catalytic effect on the hydrogen absorption–desorption reactions in the Mg−H2 system. The hydrogen storage kinetics is not influenced by different rare earth metal hydrides but by the particle size of the rare earth metal hydrides.

► We compare the hydrogenation behaviors of the melt-spun Mg10NiR alloys. ► Rare earth metal hydrides provide a catalytic effect on Mg–H2 system. ► The hydrogen storage kinetics can be enhanced remarkably.