Ni, Beyond Thermodynamic Tuning, Maintains The Catalytic Activity Of V Species In Ni-3(Vo4)(2) Doped Mgh2

Magnesium hydride has been regarded as a promising hydrogen storage material. However, its further commercialization is severely hampered by its stable thermodynamic and sluggish kinetic performance. Herein, to simultaneously solve above two problems, a bimetallic oxide Ni-3(VO4)(2) has been synthesized and applied to catalyze the hydrogen storage reaction of MgH2. Benefiting from the formation of the Mg2Ni alloy, as well as kinetic modulation of V, the dehydrogenation temperature decreased to 210 degrees C, with a promising rehydrogenation capacity of 2.3 wt% near room temperature. X-ray absorption spectroscopy was employed to comprehensively reveal local structures of Ni and V in different states, with the detection of NiV2O4 intermediate active species for the first time. This work not only elucidates the structure evolution of the Ni-3(VO4)(2) catalyst, but also clarifies the synergistic effect between Ni and V, which sheds light on further rational designs for multi-element metallic catalysts.