Interface-Engineered TiV Bimetal Catalysts with Synergistic Effects for Enhancing Hydrogen Storage Performance in Mg–Ni-Based Material

Improving the low temperature hydrogen storage kinetics of Mg-based alloys is challenging due to the antagonistic effects of elements on hydrogen dissociation and diffusion during hydrogen absorption/desorption critically determining the hydrogen storage properties of materials, but the synergistic catalytic effect of different elements offers a promising way to address these issues. This study fabricated TiV alloy through high-energy ball milling and subsequently integrated them with Mg-Ni to establish a multiphase composite system for enhanced hydrogen storage applications. Through systematic characterization, we elucidated the synergistic interactions between hydrogenophilic (Ti/V) and hydrogen-repellent elements (Ni) in regulating hydrogenation thermodynamics and kinetics. The TiV-modified Mg-20Ni composite exhibited accelerated dehydrogenation kinetics, achieving 3.0 wt % hydrogen desorption within 40 min at 225 °C. Differential scanning calorimetry (DSC) analysis revealed a reduced desorption activation energy of 82.0 kJ/mol for the TiV-containing composite, representing a sharp decrease compared with the baseline Mg-20Ni system. The enhanced sorption kinetics might originate from TiV-catalyzed Mg-H bond destabilization and asymmetric hydride phase transformations during hydrogen cycling.