Mn 3 O 4 Nanocube: An Efficient Electrocatalyst Toward Artificial N 2 Fixation to NH 3 .

Traditionally, ammonia (NH3 ) 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 NH3 synthesis, but an efficient electrocatalyst is a prerequisite for NH3 production. In this communication, the first experimental demonstration that Mn3 O4 nanocubes can be used as an efficient non-noble-metal electrocatalyst for N2 reduction reaction (NRR) at ambient conditions is reported. In 0.1 m Na2 SO4 aqueous solution, the catalyst delivers excellent NRR activity with an NH3 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.