In situ synchrotron X-ray diffraction study on the dehydrogenation behavior of LiAlH4-MgH2 composites

Abstract Dehydrogenation behavior of LiAlH 4 –MgH 2 composites was investigated by using thermal gravimetric analysis (TGA) and in situ synchrotron X-ray diffraction (XRD) technique. The experimental results showed that MgH 2 could play a catalytic role in lowing the initial dehydrogenation temperature of LiAlH 4 . Besides, MgH 2 could be destabilized by the dehydrogenation reaction products of LiAlH 4 . The initial dehydrogenation temperature of LiAlH 4 –MgH 2 composites was as low as 145 °C and MgH 2 could decompose below 300 °C. The compounds such as LiMgAlH 6 , Al 3 Mg 2 , Al 12 Mg 17 and Li 0.92 Mg 4.08 formed during dehydrogenation process suggested some mutual reactions proceeded between LiAlH 4 and MgH 2 .