The catalytic effect of spherical NiMOF on the hydrogen storage performance of MgH2

In this study, a thermally stable spherical NiMOF was introduced into MgH2 to enhance its hydrogen storage performance. The NiMOF was synthesized via a solvothermal method, and MgH2-x wt.% NiMOF (x = 3, 5, 10, 15) composites were prepared by ball milling. The MgH2-10 wt% NiMOF composite showed the best performance, with a maximum hydrogen storage capacity of 6.4 wt% under 4.2 MPa at 548 K. It absorbed 4.0 wt% H2 in 5 min and 5.2 wt% in 30 min at 548 K and 3.1 MPa. The composite demonstrated excellent cyclic stability, retaining 5.0 wt% capacity after 10 cycles. Activation energies were 64.74 kJ/mol for hydrogenation and 119.596 kJ/mol for dehydrogenation.