A Minireview on Porphyrin and Phthalocyanine Based Catalysts for Electrocatalytic Synthesis of Ammonia

Abstract Ammonia (NH 3 ) is an important raw material in the chemical industry, but the synthesis of NH 3 by the traditional Haber‐Bosch process will increase the carbon footprint. Therefore, it is necessary to develop sustainable routes for NH 3 production. New NH 3 production schemes, including nitrogen reduction (N 2 RR), nitrite reduction (NO 2 RR), and nitrate reduction (NO 3 RR), have been proposed. Porphyrins and phthalocyanines are macrocyclic compounds with a central metal ion coordinated with nitrogen. The metal centers in these catalysts play a crucial role in binding and activating nitrogen, nitrite, and nitrate. Their unique structure allows for effective electron transfer and catalytic activation in NH 3 synthesis. Recently, metal porphyrin and phthalocyanine based catalysts have been demonstrated to be efficient in catalyzing N 2 RR, NO 2 RR, and NO 3 RR. Unfortunately, there is no review focusing on such macrocyclic catalysts for the electrocatalytic synthesis of NH 3 . In this review, we discuss the electrocatalytic reduction performances and summarize the key factors and reaction mechanisms that affect the catalytic performance of metal porphyrin and phthalocyanine based catalyst systems. This review helps to design more effective new electrocatalysts for NH 3 synthesis.