Hydrogen release capacity of the LiAlH4–MgH2 system

In this work, the hydrogen release capability of the LiAlH4–MgH2 composite system is analyzed. Analysis of the molar ratios of LiAlH4 to MgH2 shows that the LiAlH4–MgH2 sample with the molar ratio of 1:0.5 presents the largest amount of hydrogen. Further study finds that doping with the catalysts LaCl3, La2O3 and CeO2 markedly shortens the hydrogen release time of the LiAlH4–MgH2 sample, except when doping with 1 mol% CeO2. In addition, doping is found to significantly improve the amount and the rate of hydrogen release of the LiAlH4–MgH2 sample. The amount of hydrogen release by the sample doped with 3 mol% La2O3 reaches about 6.5 wt%, which is about 1.1 wt% higher than that of the undoped sample.

► LiAlH4–MgH2 sample with the molar ratio of 1:0.5 presents the largest dehydrogenation amount. ► Doping markedly shortens the dehydrogenation time of LiAlH4–MgH2 sample. ► Doping improves the amount and the rate of hydrogen release of the LiAlH4–MgH2 sample.