Comparison of commercial and hydriding-combustion-synthesized Mg-hydride

This study employed a fast, simple and cost-effective hydriding combustion synthesis (HCS) to prepare nano/submicron Mg based alloys, which are the most promising solid state hydrogen storage materials owing to their high storage capacity (7.6 wt.%) and highest volumetric density. The microstructural and absorption/desorption kinetic properties of the prepared MgH2 samples were characterized and compared with commercially available MgH2 powders. The detailed BET analysis of the HCS prepared samples showed a higher surface area than that of commercial MgH2, which resulted in better absorption/desorption kinetics. The HCS-prepared MgH2 powder absorbed 6.2 wt.% H2 with a rate of 0.31 wt.%/min, whereas it desorbed at a rate of 0.98 wt.%/min. These results highlight the superiority of the HCS method to prepare MgH2 powders over conventional ingot-metallurgy.

► Comparison of HCS-MgH2 powder with the commercial one is reported. ► Comparison of micro-structural and H2 kinetics affirms the importance of HCS method. ► The HCS-MgH2 absorbed 6.2 wt.% of H2 (0.31 wt.%/min) and desorption rate was 0.98 wt.%/min.