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

The high dehydrogenation temperature of α-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 α-AlH3. The dehydrogenation onset temperature of α-AlH3+5 wt% Bi@C drop to 80.4 °C, which is reduced by 43.4% compared with pure α-AlH3. At 120 °C, it can provide a stable hydrogen capacity of 7.45 wt%. In contrast, pure α-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 α-AlH3, providing a good prospect for the application of α-AlH3 in hydrogen storage.