Effect of TixAly catalysts on hydrogen storage properties of LiAlH4 and NaAlH4

The high catalytic activities of TiCl4 and TiCl3 on the hydrogen storage properties of alkali metal aluminum hydrides have been attributed to intermetallic TiAl3. Therefore, in this work, the hydrogen storage properties of LiAlH4 and NaAlH4 doped with titanium aluminum alloys were investigated. The dopants were incorporated into the alanates by ball milling. The catalysts studied included TiAl3, Ti3Al, elemental titanium, and elemental aluminum. Ball milling in the absence of the catalyst was found to decrease the release temperature of hydrogen. Doping LiAlH4 with Ti3Al, TiAl3 and elemental aluminum additionally reduced the temperature required for hydrogen release. That effect was not observed for mixtures with NaAlH4.