Comparative study on the dehydrogenation properties of TiCl4-doped LiAlH4 using different doping techniques

Lithium aluminum hydride (LiAlH4) is an attractive hydrogen storage material because of its comparatively high gravimetric hydrogen storage capacity. In this study, titanium tetrachloride (TiCl4), which is liquid at room temperature, was chosen as dopant because of its high catalytic efficiency regarding the dehydrogenation of LiAlH4. Three low-energy doping methods (additive dispersion via ball milling at low rotation speed, magnetic stirring and magnetic stirring in ethyl ether) with different TiCl4 concentrations were compared in order to obtain optimum dehydrogenation properties of LiAlH4. At 80 °C, TiCl4-doped LiAlH4 can release up to 6.5 wt.%-H2, which opens the way to use of exhaust heat of PEM fuel cells to trigger the hydrogen release from LiAlH4.

► LiAlH4 was doped with TiCl4 using three different doping techniques.
► Optimum dehydrogenation properties were found testing various TiCl4 concentrations.
► TiCl4-doped LiAlH4 can release up to 6.5 wt.% hydrogen.
► Dehydrogenation kinetics of TiCl4-doped LiAlH4 was studied systematically at 80 °C.