Progress of metal hydrides, amides and imides for ammonia synthesis and decomposition

Ammonia, as a key feedstock for nitrogen fertilizers, also plays a crucial role as an energy and hydrogen carrier in the storage and conversion of renewable energy. The synthesis and decomposition of ammonia are central to realizing its full potential in these applications. Recent studies have highlighted the versatile chemical interconversions of alkali/alkaline metal hydrides, amides, and imides exhibit with N₂, H₂, or NH₃. Building on these findings, a series of highly efficient catalysts and novel processes for ammonia synthesis and ammonia decomposition have been developed. This review comprehensively summarizes recent progress in utilizing these compounds as functional materials for catalytic and chemical looping processes in ammonia synthesis and decomposition. Special attention is given to the unique roles of hydrides, amides, and imides in activating and transforming N₂ and NH₃, their distinct reaction mechanisms, and discuss the current challenges and future prospects of these materials in ammonia synthesis and decomposition process.