International Journal of Energy Research, Vol.42, No.3, 1139-1147, 2018
The enhanced de/re-hydrogenation performance of MgH2 with TiH2 additive
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 degrees C which is 100 degrees C and 190 degrees 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.
Keywords:hydriding;dehydriding properties;hydrogen storage;magnesium hydride;titanium hydride;transition metal hydrides