Superior catalytic effect of VO2F on dehydrogenation of magnesium hydride

Magnesium hydride has been regarded as one of the potential hydrogen storage materials, and doping with an efficient catalyst is believed to be critical to enhancing its dehydrogenation kinetic property. Herein, high-purity nanocrystalline VO₂F is synthesized as a catalyst by the mechanochemical reaction between V₂O₅ and VOF₃ under argon atmosphere. After introducing 3 mol% of VO₂F catalyst to MgH₂, the multivalent vanadium species, MgF₂ and MgO are in situ formed to accelerate dehydrogenation reaction and prevent powder agglomeration. Consequently, the MgH₂−3 mol% VO₂F composite shows the dehydrogenation activation energy of 80.6 kJ mol⁻¹. Even after 50 cycles, hydrogen capacity can be retained at 97.6 %. This approach may prove valuable for future investigations into catalyzed MgH₂-based composites.