Enhanced dehydrogenation/hydrogenation kinetics of the Mg(NH_2)_2 2LiH system with NaOH additive

摘要

The effects of NaOH addition on hydrogen absorption/desorption properties of the Mg (NH_2)_2-2LiH system were investigated systematically by means of dehydrogenation/ hydrogenation measurements and structural analyses. It is found that the NaOH-added Mg(NH_2)2-2LiH samples exhibit an enhanced dehydrogenation/hydrogenation kinetics. In particular, a ~36 ℃ reduction in the peak temperature for dehydrogenation is achieved for the Mg(NH_2)2-2LiH-0.5NaOH sample with respect to the pristine sample. Structural examinations reveal that NaOH reacts with Mg(NH_2)_2 and LiH to convert to NaH, LiNH_2 and MgO during ball milling. Then, their co-catalytic effects result in a significant improvement in the dehydrogenation/hydrogenation kinetics of the Mg(NH_2)_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.