Mn₃O₄ Nanocube: An Efficient Electrocatalyst Toward Artificial N₂ Fixation to NH₃

Traditionally, ammonia (NH 3 ) is synthesized via the Haber–Bosch process, which is not only commanded by harsh conditions but causes serious environmental pollution. Electrochemical reduction is recognized as a mild and environmentally benign alternative approach for NH 3 synthesis, but an efficient electrocatalyst is a prerequisite for NH 3 production. In this communication, the first experimental demonstration that Mn 3 O 4 nanocubes can be used as an efficient non‐noble‐metal electrocatalyst for N 2 reduction reaction (NRR) at ambient conditions is reported. In 0.1 m Na 2 SO 4 aqueous solution, the catalyst delivers excellent NRR activity with an NH 3 yield of 11.6 µg h −1 mg −1 cat. and Faradaic efficiency of 3.0% at −0.8 V versus reversible hydrogen electrode. Notably, this catalyst also possesses satisfactory durability during the electrolysis and recycling test.