Advancements in Catalytic Technologies for Chemical Hydrogen Storage: Materials, Mechanisms, and Future Prospects

The realization of a hydrogen economy depends critically on the development of storage technologies that are safe, efficient, and adaptable across diverse applications. Chemical hydrogen storage offers notable advantages in terms of energy density, safety, and system integration, making it a compelling route for large-scale applicability. We present a comprehensive review highlighting recent advancements in catalytic technologies for chemical hydrogen storage, with a primary emphasis on liquid organic hydrogen carriers (LOHCs) and ammonia (NH₃) as representative storage media. The roles of catalytic systems in governing hydrogenation and dehydrogenation reactions are examined in detail, spanning noble metal systems, cost-effective transition-metal alternatives, and emerging bimetallic and alloy catalysts. Critical challenges, including thermodynamic and kinetic barriers, catalyst deactivation, cost, and reversibility, are discussed as key hurdles in realizing practical systems. Recent advances in single-atom catalysts (SACs), nano-engineered catalysts, bimetallic systems, and mechanistic understanding of hydrogenation-dehydrogenation pathways are highlighted as promising strategies to overcome these limitations. Finally, this contribution outlines future research priorities in LOHCs dehydrogenation and NH₃ decomposition with the overarching goal of bridging catalyst innovation with sustainable hydrogen storage solutions, thereby supporting the global transition toward a carbon-neutral energy economy. Unlike previous reviews focusing on individual storage routes, this work integrates advances in LOHCs and NH₃ decomposition catalysts within a single framework, emphasizing mechanistic insights and material innovations for scalable hydrogen storage.