Effect of La3+ on Dehydrogenation Capacity of the LiAlH4− NH4Cl System

The effect of the catalysts LaCl3 and La2O3 on the dehydrogenation properties of the LiAlH4-NH4Cl system was analyzed. The results show that La2O3 doping shortens the starting time of hydrogen release, and improves the rate of hydrogen release. While, LaCl3 doping induces an obvious decrease of the rate of hydrogen release. Furthermore, the study shows that with the increase of the amounts of LaCl3 and La2O3, the hydrogen release amounts of the samples present a gradual decrease within 180 min except for the sample doped with 3 mol% LaCl3. However, the maximum hydrogen release amount of the sample doped with La2O3 is obviously higher than that of the sample doped with LaCl3. In addition, the analysis of the SEM images of the undoped sample and the doped samples indicates that the microstructure of all the samples seems to be similar and obvious differences are not found.