Recent research progress of catalysts for thermocatalytic ammonia decomposition

With the global energy transition underway, hydrogen has gained attention as a clean energy source. However, its large-scale application is limited by challenges such as storage and transportation difficulties, low energy density, and the hard-to-detect nature of leaks. In contrast, ammonia, as an efficient hydrogen carrier, offers advantages such as high hydrogen storage capacity, low cost, mature storage and transportation methods, and safety. Ammonia cracking is crucial for harnessing ammonia as a hydrogen carrier, and on-site hydrogen production can effectively address the challenges associated with traditional hydrogen usage. Hence, this paper provides a deep and thorough review for thermocatalytic ammonia decomposition, including the effects of catalyst fabrication approach, supports, promoters and other factors on the catalytic activity, focusing on the reaction kinetics, rate-determining steps, their influencing factors, and the key reaction steps and mechanisms, Special attention is paid to Co catalysts which is potential for ammonia decomposition at low temperatures. This review reveals the basic principles of catalytic NH₃ decomposition, summarizes the strategies for improving reaction efficiency, and can serve as a comprehensive reference and theoretical guidance for the design of new catalysts reaction processes.