Improvement in hydrogen storage performance of MgH2 by vanadium doped with ZIF-8 derived a single-atom catalyst V–N–C

Herein, the successful preparation of a single-atom catalyst V–N–C using vanadium-doped zeolitic imidazolate framework (ZIF)-8 as a precursor is reported. The experimental results showed that the V–N–C had a good promoting effect on the hydrogen storage performance of MgH 2 , and the optimal addition amount of V–N–C was 10 wt%. The hydrogenation and dehydrogenation apparent activation energies of 10 wt% V–N–C-catalyzed MgH 2 were reduced by 44.9 and 53.5 kJ·mol −1 , respectively, compared to those of additive-free MgH 2 . The 10 wt% V–N–C-catalyzed MgH 2 could reabsorb 5.92 wt% of hydrogen in 50 min at 150 °C, with a capacity retention rate of 99.1% after 30 cycles of hydrogen absorption and desorption. Mechanism analysis showed that V–N–C was partially transformed into VN and metallic V when it was milled with MgH 2 ; the in-situ-formed VN and metallic V played an important role in improving the hydrogen storage performance of MgH 2 . This approach provides a potential solution for obtaining high-performance Mg-based hydrogen storage materials through synergistic interactions between V, N and C. Graphical abstract