Effect of Ti Intermetallic Catalysts on Hydrogen Storage Properties of Magnesium Hydride

Magnesium hydride is a promising candidate for solid-state hydrogen storage and thermal energy storage applications. A series of Ti-based intermetallic alloy (TiAl, Ti3Al, TiNi, TiFe, TiNb, TiMn2, and TiVMn)-doped MgH2 materials were systematically investigated in this study to improve its hydrogen storage properties. The dehydrogenation and hydrogenation properties were studied by using both thermogravimetric analysis and pressure–composition–temperature (PCT) isothermal to characterize the temperature of dehydrogenation and the kinetics of both desorption and absorption of hydrogen by these doped MgH2. Results show significant improvements of both dehydrogenation and hydrogenation kinetics as a result of adding the Ti intermetallic alloys as catalysts. In particular, the TiMn2-doped Mg demonstrated extraordinary hydrogen absorption capability at room temperature and 1 bar hydrogen pressure. The PCT experiments also show that the hydrogen equilibrium pressures of MgH2 were not affected by these additives.