From Ammonia to Hydrogen: Evolution of Ruthenium-Based Catalysts

Ammonia decomposition provides an efficient method for hydrogen production, facilitating its storage and transportation. Ruthenium is extensively used as a catalyst for this process owing to its considerable catalytic activity. Recent studies have focused on reducing ruthenium usage and enhancing its activity at lower temperatures by exploring various promoters, support materials, and various experimental conditions. This review explores recent advancements in the field of ammonia decomposition using ruthenium-based catalysts. It focuses on the development of core–shell structured catalysts, incorporation of secondary metals like Fe, La and Ni and use of precise synthesis methods like coprecipitation, deposition-precipitation, and wetness impregnation. The importance of promoters such as alkali, alkaline earth, and rare earth metals is emphasized, along with a detailed discussion on support materials like graphene, carbon nanotubes (CNTs), Al2O3, SiO2, and MgO. Collectively, these strategies lead to improved metal dispersion, thermal stability, catalytic activity, and overall performance. These findings underscore the strong potential of ruthenium-based catalysts for ammonia decomposition and offer valuable insights for the development of efficient low-temperature catalysts for large-scale hydrogen production.