Ammonia has attracted much attention as a new energy carrier. However, efficient catalytic ammonia oxidation to nitrogen has not been well developed, because it involves a challenging six-electron oxidation reaction. Macrocyclic metal complexes such as porphyrins and phthalocyanines have been reported as water oxidation catalysts — which involve a four-electron process — and operate via a bimolecular mechanism. This bimolecular mechanism is important for promoting ammonia oxidation efficiently, since only a three-electron oxidation of the catalyst is required. This study aims to achieve highly efficient ammonia oxidation using a novel macrocyclic molecular catalyst.

Ammonia has attracted much attention as a new energy carrier. However, efficient catalytic ammonia oxidation to nitrogen has not been well developed, because it involves a challenging six-electron oxidation reaction. Macrocyclic metal complexes such as porphyrins and phthalocyanines have been reported as water oxidation catalysts — which involve a four-electron process — and operate via a bimolecular mechanism. This bimolecular mechanism is important for promoting ammonia oxidation efficiently, since only a three-electron oxidation of the catalyst is required. This study aims to achieve highly efficient ammonia oxidation using a novel macrocyclic molecular catalyst.