Ammonia as a Green Carbon-Free Fuel: A Pathway to the Sustainable Energy Economy

The risk associated with the transportation and storage of hydrogen gas has driven people to seek alternative fuels with better safety and more mature transportation/storage technology. Ammonia, with its high hydrogen density and well-developed storage and transportation systems, presents a viable option as either a direct fuel or hydrogen carrier. In addition, the utilization of ammonia could unlock substantial economic value and facilitate the transition toward decarbonized energy systems. On the basis of this, this review presents a comprehensive and detailed summary of the latest advancements in exploiting ammonia as a green carbon-free fuel, as a hydrogen carrier to produce H2, and as a precursor to deliver high-value-added products. This review will discuss the fundamental reaction mechanisms, recent research progress, and potential challenges in each of these areas, aiming to provide a thorough understanding of the role of ammonia in future green energy solutions and high-value chemical production.