Hydrogen storage properties of the Zintl phase alloy SrAl2 doped with TiF3

In this paper, the structural and hydrogenation characteristics of TiF3-doped Zintl phase alloy SrAl2 were studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and hydrogenation measurements. The results show that the hydrogenation kinetics of the Zintl phase alloy SrAl2 is improved greatly after doping with TiF3. By adjusting the doping amount and ball milling time, the optimal doping conditions were obtained. The catalytic mechanism of TiF3 for the hydrogenation of SrAl2 was also investigated. SrAl2 does not react with TiF3 during the ball milling process. However, it reacts with TiF3 to form SrAl2H2, SrF2, SrAl4 and Ti during the hydrogenation process, among which Ti plays an important role in the hydrogenation kinetics of SrAl2.