The enhanced de/re‐hydrogenation performance of MgH2 with TiH2 additive

Summary Catalytic effects of TiH2 on hydrogenation/dehydrogenation kinetics of MgH2 were investigated in this study. The TG analysis showed that the addition of the x wt% TiH2 exhibited lower onset temperature of 160°C which is 100°C and 190°C lower than as‐milled and as‐received MgH2. The dehydrogenation and hydrogenation kinetics were significantly improved compared with the pure MgH2. The activation energy for the hydrogen desorption of MgH2 was reduced from −137.13 to −77.58 kJ/mol by the addition of TiH2. XRD and XPS results showed that the phase of TiH2 remained same during the dehydrogenation without any intermediate formation confirming its role as catalyst. The catalytic effect of TiH2 on the sorption properties of MgH2 has been presented here. The activation energy found to be decreased to –77.58 kJ/mol by the addition of TiH2. The addition of TiH2 enables magnesium to absorb hydrogen at room temperature efficiently. The mechanism of this improvement has been studied using XPS technique.