Ti-Doped LiAlH4 for Hydrogen Storage: Synthesis, Catalyst Loading and Cycling Performance

The direct synthesis of LiAlH4 from commercially available LiH and Al powders in the presence of TiCl3 and Me2O has been achieved for the first time. The effects of TiCl3 loadings (Ti/Al = 0, 0.01, 0.05, 0.2, 0.5, 1.0 and 2.0%) and various other additives (TiCl3/Al2O3, metallic Ti, Nb2O5, and NbCl5) on the formation and stability of LiAlH4 have been systematically investigated. The yield of LiAlH4 initially increases, and then decreases, with increasing TiCl3 loadings. LiH + Al -> LiAlH4 yields above 95% were obtained when the molar ratios of Ti/Al were 0.05 and 0.2%. In the presence of a very tiny amount of TiCl3 (Ti/Al = 0.01%), LiAlH4 is still generated, but the yield is lower. In the complete absence of TiCl3, LiAlH4 does not form.Addition of metallic Ti, Nb2O5, and NbCl5 to commercial LiH and Al does not result in the formation of LiAlH4. Preliminary tests show that TiCl3-doped LiAlH4 can be cycled, making it a suitable candidate for hydrogen storage.