Multi-component synergistic catalytic effect to enhance hydrogen storage kinetic of non-activated MgH2-Ni/Ti3C2Tx composites

This is the authors' abstract. We don't add key points for this paper.

Magnesium hydride (MgH 2 ) is of significant interest for its large energy density and abundance, but its slow kinetics and high thermodynamic stability severely limit its large-scale application. The above problems are mainly attributed to the higher dissociation energy of the surface and Mg H bonds energy. In this work, a multicomponent synergistic catalytic effect was achieved by introducing Ni/Ti 3 C 2 T x catalyst. The favorable synergistic effect between Ni and Ti 3 C 2 T x led to a decrease in the peak dehydrogenation temperature of the MgH 2 -Ni/Ti 3 C 2 T x -0.5 to 417.38 °C, while also decreasing the Ea to 146.32 kJ·mol −1 . Furthermore, the MgH 2 -Ni/Ti 3 C 2 T x -0.5 composite demonstrated an absorption capacity of 6.06 wt% within 60 s and a desorption capacity of 5.6 wt% of hydrogen in 240 s at 350 °C, reaching 85.7 % and 79.2 % of the theoretical capacity, respectively. The improved hydrogen storage properties are attributed to the significant refinement of the particle size by the mechanical ball milling process and the formation of multivalent Ti environment. The discoveries of this study provide an experimental basis for the construction of effective MXene catalysts and novel Mg-based hydrogen storage materials.