Superior catalytic effect of Bi@C on dehydrogenation performance of a-AlH3

The high dehydrogenation temperature of a-AlH3 has always been an important factor hindering its development. In order to solve this problem, we synthesize Bi-MOF by hydrothermal method and burn it under inert gas to obtain Bi@C, which is used as catalyst (xBi@C, x = 3, 5 and 7 wt%) to improve the hydrogen desorption performance of a-AlH3. The dehydrogenation onset temperature of a-AlH3+5 wt% Bi@C drop to 80.4 degrees C, which is reduced by 43.4% compared with pure a-AlH3. At 120 degrees C, it can provide a stable hydrogen capacity of 7.45 wt%. In contrast, pure a-AlH3 releases only 6.66 wt% hydrogen at the same time. The density functional theory calculations further indicate that the existence of Bi@C catalyst can make the Al-H bond length increase, more conducive to the release of hydrogen. The results show that the synergistic effect of Bi and porous carbon in Bi@C materials can improve the hydrogen desorption kinetics of a-AlH3, providing a good prospect for the application of a-AlH3 in hydrogen storage.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.