Catalytic Effect of Ti on H-Desorption/Absorption Properties in MgH2 Prepared by Ball Milling

We report on the preparation and hydrogen desorption/absorption kinetics of nanocrystalline magnesium hydride (MgH2) added commercial Ti by high-energy ball milling. The phase and composition of the as-milled powders are characterized by X-ray diffraction (XRD). The results show that the milled sample contained MgH2 phase, Ti phase and small amount of MgO phase. When the milling time is 30 h, the hydrogen desorption property of MgH2 has been investigated and found that the sample releases 0.43, 0.86 and 0.90 wt% H2 in 200 minutes at 280, 290 and 300 oC , respectively. Moreover, the sample absorbs 0.48, 0.0.58 and 0.61 wt% H2 in 15 minutes at 280, 290 and 300 oC , respectively. It can be seen that the kinetics of hydrogen desorption/absorption of MgH2-Ti composite has been greatly enhanced compared to the pure MgH2.