MXene-Catalyzed Hydrogen Storage Enhancement in AZ31 Magnesium Alloy: Integration of V2C

This study investigates the catalytic effect of V 2 C MXene on the hydrogen storage properties of AZ31 magnesium alloy. Using high-energy ball milling, we made composites based on AZ31 with 1, 3, and 6 wt.% V 2 C. Microstructural studies (SEM, EDS, and XRD) validated the homogeneous distribution of V 2 C and the integrity of the primary Mg matrix, with only negligible interfacial phase development. The kinetics and capacity of hydrogen sorption were assessed utilizing a Sieverts-type device at temperatures ranging from 325 to 375 °C. The AZ31–1 wt.% V 2 C composite exhibited superior performance, attaining a hydrogen capacity of 6.64 wt.% with markedly accelerated absorption kinetics (1258 s) relative to pure AZ31 (6.14 wt.%, 2094 s) at 375 °C. Kinetic research using JMAK and reduced-time models indicated a diffusion-controlled absorption mechanism, while Arrhenius analysis suggests a significant decrease in activation energy from 159.7 kJ/mol for AZ31 to 101.7 kJ/mol for the 1 wt.% V 2 C composite. The findings indicate that V 2 C serves as an effective catalyst, promoting hydrogen dissociation and transport at the magnesium interface. When too much V 2 C (6 wt.%) was added, the particles stuck together, and the kinetics sped up but the reversible capacity went down. This study demonstrates that a low, regulated concentration of V 2 C MXene effectively improves the hydrogen storage capacity of magnesium alloys.