Effect of Eu2O3@C composite catalyst on hydrogen storage performance of Mg96La3Ni alloy

Abstract

This study successfully synthesized Eu2O3@C composite catalyst by an improved chemical blowing method. The Eu2O3 nanoparticles in this catalyst are highly dispersed within a porous carbon matrix, exhibiting a well-developed mesoporous structure, a large specific surface area, and a high density of defects. Eu2O3@C was mixed with the Mg96La3Ni alloy through ball milling, and the impact of varying amounts of Eu2O3@C on the hydrogen storage performance of Mg96La3Ni was comprehensively investigated. The results showed that Eu2O3@C markedly enhances the de/hydrogenation kinetics of Mg96La3Ni, with the most substantial impact noted at a Eu2O3@C content of 2 wt %. At 360 °C, 77.3 % of the maximum hydrogen capacity could be absorbed within 2 min, while only 1.4 min was required to release 3 % of hydrogen. Additionally, Eu2O3@C markedly decreased the dehydrogenation activation energy of the alloys to 106.3 kJ/mol and reduced the endothermic peak temperature to 347 °C, while leaving thermodynamic properties unaffected. The Mg96La3Ni–Eu2O3@C composite exhibits remarkable cyclic stability, retaining its hydrogen storage capacity throughout the cycling process. This study pioneers a novel strategy to elevate the performance of magnesium-based hydrogen storage materials.