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.