Research Progress on Cerium-Based Catalysts for Mg-Based Hydrogen Storage Materials: Structural Regulation and Catalytic Mechanisms

Magnesium-based hydrogen storage materials have attracted extensive attention due to their high hydrogen storage capacity, natural abundance, and economic advantages. However, their practical applications remains constrained by strong Mg-H bonding, high dehydrogenation temperatures, and sluggish hydrogen sorption kinetics. Cerium-based catalysts, benefiting from their reversible valence transitions, abundant defect structures, and tunable interfacial electronic properties, provide an effective strategy for enhancing the hydrogen storage performance of Mg-based materials. This review provides a comprehensive overview of recent advances in metallic Ce and Ce-containing alloys, cerium-based halides, CeO 2 -based catalysts, and composite Ce-based catalytic systems. The relationships among catalyst composition, structural evolution, and hydrogen storage performance are systematically discussed, with particular emphasis on electronic structure regulation and Mg-H bond activation, H 2 molecule activation and hydrogen spillover, heterogeneous interface engineering, and dynamic active phase evolution. Accumulated evidence suggests that Ce valence transitions, oxygen vacancies, heterogeneous interfaces, and in situ generated active species such as CeHx during hydrogen cycling synergistically facilitate electron transfer, hydrogen migration, and Mg/MgH 2 phase transformation. Finally, current challenges and future perspectives are proposed, focusing on active phase identification, rational interfacial engineering, and multi-component synergistic design of high-performance Ce-based catalysts. Through multicomponent synergistic coupling and dynamic interface design, Ce-based catalysts show substantial potential for lowering dehydrogenation activation barriers and improving cycling stability, thereby providing a promising route toward practical Mg-based hydrogen storage.