Al–Li3AlH6: A novel composite with high activity for hydrogen generation

•Li3AlH6 as promoter additive for Al–H2O reaction with very high activity.•Li3AlH6 provides an additional H2 source and an alkaline environment.•Conversion efficiency of composite is about 100% by adjusting Li3AlH6 content.•H2 released capacity of Al–Li3AlH6 composite is larger than that of pure Al.•At 25 °C, H2 yield of Al-20 wt% Li3AlH6 is 1513.1 mL/g.

A novel material for hydrogen generation with high capacity of H2 generation has been successfully prepared by ball milling the mixture of Al and home-made fresh Li3AlH6 powder. Its theoretical capacity of hydrogen released is higher than that of pure Al. Results obtained have shown conversion efficiency of Al–Li3AlH6 composite can be close to 100% by increasing the content of Li3AlH6. When the content of Li3AlH6 is 20 wt%, the maximum hydrogen generation rate and hydrogen yield are 2737.6 mL g−1 min−1 and 1513.1 mL g−1, respectively, at room temperature. By XRD, SEM analyses and reaction heat measurements, it demonstrates that the additive Li3AlH6 can provide an additional source of H2 and an alkaline environment (LiOH) as well as additional heat to promote the Al/H2O reaction. Therefore, the Al–Li3AlH6 composite has a very high activity and high capacity of hydrogen released.