Effect of Ti catalyst with different chemical form on Li-N-H hydrogen storage properties

The effect of some different type Ti additives on kinetics of the reaction, LiH+LiNH2↔Li2NH+H2, was intensively investigated in this work. The mixture of LiH and LiNH₂ powders with the 1:1 molar ratio and Ti additives with different chemical form were mechanically ball milled under a hydrogen gas atmosphere of 1 MPa at 400 rpm for 2 h and the measurements of thermal hydrogen desorption spectrum (TDS), thermogravimetry (TG) and X-ray diffraction (XRD) were performed. Here, we used Ti (nano particle), Ti (micro particle), TiCl ₃, TiO₂ (nano particle) and TiO₂ (micro particle) as the additives. The results indicated that the Ti^nano, TiCl₃ and TiO2nano doped composites revealed a superior catalytic effect on the TDS properties, while the Ti^micro and TiO2micro did not show so good catalytic effect being similar to the sample without any additives. In the XRD profiles, there are traces of Ti and TiO₂ phases in the Ti^micro and TiO2micro doped composites, respectively, whereas no trace of Ti, TiCl₃ and TiO₂ was found in the Ti^nano, TiCl₃ and TiO2nano doped composites. These results indicate that the uniform distribution of nano particle Ti metal between LiH and LiNH₂ plays an important role for catalytic effect.