Excellent catalytic effect of V2C MXene on dehydrogenation performance of α-AlH3

Lowering the dehydrogenation temperature and maintaining high dehydrogenation capacity are greatly hindering the practical application of α-AlH3 for the hydrogen fuel cell industry. Herein, the layered accordion-like V2C MXene is synthesized and doped into α-AlH3 by mild ball milling. The 1 wt.% V2C-catalyzed α-AlH3 possesses excellent dehydrogenation performance with a low initial decomposition temperature of 70.5 °C and a high hydrogen release capacity of 8.1 wt.%. Furthermore, 7.8 wt.% of hydrogen could be quickly released from α-AlH3-1 wt.% V2C composite within 15 min at 120 °C, with a lower activation energy of 69.5 kJ/mol than that of as-received sample. The excellent dehydrogenation performance is attributed to the high activity of the zero valence V catalyst which is transformed from the multivalent V during ball milling and to promote dissociation and reorganization of hydrogen. This effective approach significantly enhances the dehydrogenation of α-AlH3, providing a hopeful approach for modifying metal hydrides.