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 + H-2, 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 I MPa at 400 rpm for 2 It 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), TiCl3, 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. (c) 2005 Elsevier B.V. All rights reserved.