GdO@C composite catalyst for enhanced hydrogen storage performance of Mg–La–Ni alloy.

GdO@C composite catalyst synthesis was achieved through a novel chemical blowing carbonization method. Nano-sized GdO uniformly distributed throughout a high-surface-area, defect-laden carbon matrix translates to catalytic performance. To elucidate the influence of GdO@C doping on hydrogen storage, Mg 96 La 3 Ni-GdO@C alloys were prepared by ball milling, and the hydrogen storage performance was evaluated. Adding GdO@C can refine the alloy particles, which boosts the surface area and the number of active sites available for the hydrogenation reaction. GdO@C greatly enhanced the de/hydriding kinetics of the alloys, with 1 wt% GdO@C exhibiting the optimal effect. At 360 °C, this material could quickly absorb a large amount of hydrogen (84.4 wt% of its maximum capacity) in just 2 min, but it only took 1.6 min to release a small amount (3 wt%). Doping the alloys with GdO@C reduced the activation energy barrier for dehydrogenation (to 106.3 kJ/mol) and shifted the endothermic peak to a lower temperature (334 °C). Nevertheless, there was no improvement observed in the thermodynamic properties of the composites, as the enthalpy change remained constant at 77.1 kJ/mol. • GdO@C composite catalyst was successfully synthesized by an improved chemical blowing method • The GdO@C has a mesoporous structure, large specific surface area, and high defect density. • GdO@C addition refines particle size, increases surface area and active sites. • GdO@C greatly improved hydrogen de/hydriding kinetics of Mg 96 La 3 Ni. • Adding 1 wt% GdO@C lowered the alloy's dehydrogenation activation energy to 106.3 kJ/mol. • The addition of GdO@C catalyst does not effectively improve the thermodynamic properties of the alloy [ABSTRACT FROM AUTHOR]