Nanostructured Catalysts for Enhanced Hydrogen Sorption in Metal Hydrides: Recent Advances and Future Perspectives

Hydrogen is widely recognized as a promising clean energy carrier for a sustainable, low-carbon future. Nanostructured metal hydrides have emerged as favorable hydrogen storage materials because their properties can be tailored more effectively than those of bulk hydrides. Compared with bulk materials, nanostructured metal hydrides exhibit improved reversibility, tunable hydrogen absorption/desorption thermodynamics, accelerated hydrogen sorption kinetics, and enhanced surface reactivity. However, their practical application remains limited by sluggish hydrogen sorption kinetics, high operating temperatures, and poor cycling stability. To overcome these limitations, nanostructured catalysts have emerged as an effective strategy for reducing kinetic barriers and improving reversible hydrogen storage performance. This review critically examines recent advances in nanostructured catalysts for improving hydrogen storage in metal hydrides. It covers a broad range of catalyst systems, including transition-metal nanoparticles, metal oxides, metal halides, carbides, nitrides, carbon-based materials, MXene-supported catalysts, and hybrid nanostructures. Their catalytic mechanisms, interactions with metal hydride matrices, and their effects on hydrogen sorption kinetics and storage performance are systematically discussed. Reported studies demonstrate that these catalysts can reduce hydrogen desorption temperatures by 50–200 °C, lower activation energies by 20–60%, and significantly enhance hydrogen absorption/desorption kinetics and cycling stability. The review further discusses key challenges, including catalyst stability, scalable synthesis, cost, and longterm durability. Finally, it outlines future research directions focused on interface engineering, multifunctional hybrid catalysts, MXene-supported materials, high-entropy alloy catalysts, and data-driven materials discovery. By integrating recent developments with emerging opportunities, this review provides valuable insights into the rational design of high-performance nanostructured catalysts for efficient, reversible, and practical hydrogen storage in sustainable energy systems.