Zn2TiO4 synthesized via solid-state method and its effects on dehydrogenation properties of LiAlH4

Abstract

Lithium alanate (LiAlH4) has high gravimetric capacity but its practical application is still severely constrained by poor reversibility and sluggish kinetics. In this study, the dehydrogenation behaviour of LiAlH4 was modified with the inclusion of Zn2TiO4. The initial temperature for the dehydrogenation of LiAlH4 was downshifted to 111 °C (first dehydrogenation) and 151 °C (second dehydrogenation) with the inclusion of 10 wt% Zn2TiO4. The as-milled LiAlH4 released only 0.1 wt% H2 while the LiAlH4–10 wt% Zn2TiO4 sample released 3.6 wt% H2 in 60 min at 90 °C which is 36 times faster than undoped LiAlH4. The dehydrogenation activation energies for the first two dehydrogenation process was also reduced by 24.1 and 21.0% than as-milled LiAlH4. The X-ray diffraction analysis revealed that the Zn2TiO4 reacts with LiAlH4 and the formed Al–Ti and Ti–Zn during the dehydrogenation leading to the superior dehydrogenation behaviour of LiAlH4.