Recent advances in thermocatalytic ammonia synthesis and decomposition

Ammonia (NH₃) is widely used in the production of vital chemicals such as synthetic fertilizers and nitric acid. It has recently attracted great attention as an energy carrier due to its high hydrogen content (17 wt.% H), ease of transportation, and stability over time. However, for ammonia to fulfil this promise, a more efficient and sustainable method for its synthesis and decomposition must be developed. Significant scientific efforts have been devoted to achieving this via an in-depth understanding of the reaction mechanisms. This mini-review discusses the most relevant developments in heterogenous catalysts for ammonia synthesis and decomposition over the past two years, which has centered on structural and electronic modifications, single atom catalysis, and the use of dual/multiple catalytic sites for N₂ and H₂ activation to overcome the scaling relationship, and thereby achieve moderate reaction conditions.