Enhancement of dehydrogenation properties in LiAlH4 catalysed by BaFe12O19

In this work, we investigated the effects of BaFe12O19 on the dehydrogenation properties of LiAlH4. It was shown that the LiAlH4 doped with 10 wt% of BaFe12O19 had started to release hydrogen at 95 degrees C, as compared with undoped LiAlH4 (more than 140 degrees C). Desorption kinetic result showed that the BaFe(12)O(19-)doped LiAlH4 sample can release more hydrogen (4.2 wt% of H-2) compared to undoped LiAlH4 (less than 1.0 wt%) at 90 degrees C for 2.5 h. Results of differential scanning calorimetry measurements showed that the thermal events had remained the same for the BaFe12O19-doped LiAlH4 sample and the undoped LiAlH4. However, thermal events occurred at a lower temperature after the addition of 10 wt% BaFe12O19. The desorption activation energies of the first two reactions for the BaFe12O19-doped LiAlH4 sample were decreased by about 32 kJ/mol and 22 ki/mol, compared to undoped LiAlH4, respectively. Scanning electron microscopy images revealed the size of particles became smaller with the addition of BaFe12O19. It is believed that the improvements in the desorption process were catalysed by the Fe, LiFeO2 and amorphous Ba or Ba-containing that were formed in situ during the dehydrogenation process. (C) 2020 Elsevier B.V. All rights reserved.