Study on the reactivity of MgH_2 + MgB_2 composites under high hydrogen pressure and high temperature

摘要

Magnesium diboride (MgB_2) was added to MgH_2.50 wt%MgH_2 + 50 wt%MgB_2 composites were prepared by grinding under a hydrogen atmosphere (reactive mechanical grinding). Hydriding and dehydriding rates were examined for the prepared 50 wt5%MgH_2 + 50 wt%MgB_2 composites. 50 wt%MgH_2 + 50 wt%MgB_2 pellets were also prepared after reactive mechanical grinding. Hydrogen storage properties of these pellets at high temperature (823-873 K) under high hydrogen pressure (60-80 bar H_2) were then investigated. A 50 wt%MgH_2 + 50 wt%MgB_2 pellet hydrided in an autoclave at 823-923 K under 60-80 bar H_2 for 1 h desorbed 3.94 wt%H for 4 h at 673 K under hydrogen lower than 0.5 bar H_2.