On the dehydrogenation of LiAlH4 enhanced by Ti salts and cryogenic ball-milling

Abstract

Several mixtures of LiAlH4 and Ti salts (TiH2, TiF3, and TiCl4) were produced using short milling times and cryogenic (liquid nitrogen) cooling. The stoichiometric (2:1) and 5 mol% mixtures LiAlH4/TiH2 demonstrated minor improvements on the dehydrogenation temperature of LiAlH4. Conversely, an enhancement of the dehydrogenation reaction was observed in the LiAlH4 added with 5 mol% of TiCl4 and in the stoichiometric mixture 3LiAlH4 + TiF3. In these mixtures, an important reduction of the dehydrogenation temperature was observed (37 °C and 55 °C on-set temperature, respectively). This improvement was promoted by the use of cryogenic ball milling and careful control of the energy added to the mixtures during ball milling.