Spinel LiMn 2 O 4 Nanofiber: AnEfficient Electrocatalyst for N 2 Reduction to NH 3 under Ambient Conditions

The production of ammonia (NH3) in the industrial scale basically relies on the traditional technology of Haber–Bosch, which is operated under harsh conditions with high energy consumption and a huge number of greenhouse gas emissions. Electrochemical N2 reduction reaction (NRR) is a promising route for artificial N2-to-NH3 fixation with less energy consumption. However, an effective electrocatalyst, as a prerequisite of the NRR, is of significance. Here, we report that a spinel LiMn2O4 nanofiber acts as a noble-metal-free electrocatalyst for NH3 synthesis with excellent performance under ambient conditions. The electrocatalyst, which was tested in 0.1 M HCl, has an excellent Faradaic efficiency of 7.44% and a NH3 yield of 15.83 μg h–1 mgcat.–1 at −0.50 V versus reversible hydrogen electrode. Moreover, it also possesses excellent electrochemical and structure stability.