In situ oxidized MXene-supported Ru nanoparticles: A durable catalyst for high-performance MgH2 hydrogen storage

Magnesium hydride (MgH 2 ) has attracted much attention due to its high hydrogen storage capacity and low cost, but it is limited by its slow absorption/desorption kinetics and excessively high operating temperature. In this study, a multiphase synergistic Ru@TiO 2 @MXene catalyst was successfully synthesized by depositing ruthenium onto in-situ oxidized MXene. The resulting catalyst significantly improved the hydrogen absorption/desorption kinetics of MgH 2 . Experimental results demonstrate that with addition of 5 wt% Ru@TiO 2 @MXene, the MgH 2 composite exhibits a significantly reduced onset dehydrogenation temperature of 191 °C and achieves considerable hydrogen absorption at room temperature. The apparent activation energy ( E a) for MgH 2 decreases to 84.92 kJ/mol. In addition, the system maintained a high capacity retention of 97% after 150 cycles.The superior catalytic performance is attributed to the high dispersion of Ru species, the synergistic catalytic activity of multivalent Ti, and high specific surface area MXene. This work provides new insights for designing efficient MgH 2 catalysts.