Research progress of ruthenium-based catalysts for hydrogen production from ammonia decomposition

Hydrogen production by ammonia decomposition is an in-situ technology that facilitates the storage and transportation of hydrogen. Due to its excellent catalytic performance, ruthenium is widely used as a catalyst for ammonia decomposition. Recent studies have focused on the preparation methods, support structures, and promoter types for ruthenium-based catalysts, aiming to reduce the amount of ruthenium and enhance their low-temperature activity. This paper reviews the recent research progress in the mechanism, kinetics, and thermodynamics of ammonia decomposition reactions and the regulation of ruthenium-based catalyst activity. The review highlights the use of controlled preparation methods, such as wetness impregnation, deposition-precipitation, and co-precipitation, the addition of secondary metals like Ni, Fe, and La, the selection of suitable supports including CNTs, graphene, Al₂O₃, SiO₂, and MgO, the incorporation of appropriate promoters, such as alkali, alkaline earth, and rare earth metals, and the utilization of core-shell structured catalysts. These approaches improve ruthenium-based catalysts' dispersion, thermal stability, reactivity, and catalytic performance. Based on these findings, improvement measures and future directions for using ruthenium-based catalysts in ammonia decomposition are proposed, aiming to prepare low-temperature and high-activity catalysts for large-scale hydrogen production.