Effect of Yb2O3@C composite catalyst on hydrogen storage performance of Mg–La–Ni alloy

Abstract

The present study successfully synthesized a Yb2O3@C composite catalyst using an enhanced chemical blow molding carbonization method. The characterization results showed that the catalyst was highly dispersed in the porous carbon matrix by Yb2O3 nanoparticles. And the catalyst has developed pore structure, high specific surface area and high defect density. Yb2O3@C was mixed with the Mg96La3Ni alloy through ball milling, and the impact of varying amounts of Yb2O3@C on the hydrogen storage performance of Mg96La3Ni was comprehensively investigated. The research findings indicate that the addition of Yb2O3@C notably refines the Mg-based alloy, leading to an increase in both specific surface area and the count of active sites. Furthermore, Yb2O3@C markedly enhances the hydrogen sorption kinetics of Mg96La3Ni, with the most substantial impact noted at a Yb2O3@C content of 3 wt %. Additionally, the incorporation of Yb2O3@C substantially decreases the dehydrogenation activation energy of the alloy, while leaving its thermodynamic properties unaffected. Yb2O3 nanoparticles and the carbon matrix work synergistically to promote both nucleation reactions and hydrogen diffusion. This study presents a novel strategy for enhancing the performance of hydrogen storage materials based on magnesium.