Enhanced dehydrogenation/hydrogenation kinetics of the Mg(NH2)2-2LiH system with NaOH additive

The effects of NaOH addition on hydrogen absorption/desorption properties of the Mg(NH2)2-2LiH system were investigated systematically by means of dehydrogenation/hydrogenation measurements and structural analyses. It is found that the NaOH-added Mg(NH2)2-2LiH samples exhibit an enhanced dehydrogenation/hydrogenation kinetics. In particular, a ∼36 °C reduction in the peak temperature for dehydrogenation is achieved for the Mg(NH2)2-2LiH-0.5NaOH sample with respect to the pristine sample. Structural examinations reveal that NaOH reacts with Mg(NH2)2 and LiH to convert to NaH, LiNH2 and MgO during ball milling. Then, their co-catalytic effects result in a significant improvement in the dehydrogenation/hydrogenation kinetics of the Mg(NH2)2-2LiH system. This finding will help in designing and optimizing the novel high-performance catalysts to further improve hydrogen storage in the amide-hydride combined systems.