High-Efficiency Electrosynthesis of Ammonia with Selective Reduction of Nitrate in Neutral Media Enabled by Self-Supported Mn2CoO4 Nanoarray

Ambient ammonia synthesis by electroreduction of nitrate (NO 3 – ) provides us a sustainable and environmentally friendly alternative to the traditional Haber–Bosch process. In this work, Mn 2 CoO 4 nanoarray grown on carbon cloth (Mn 2 CoO 4 /CC) serves as a superior electrocatalyst for efficient NH 3 synthesis by selective reduction of NO 3 – . When operated in 0.1 M PBS with 0.1 M NaNO 3, Mn 2 CoO 4 /CC reaches a high Faraday efficiency of 98.6% and a large NH 3 yield up to 11.19 mg/h/cm 2 . Moreover, it exhibits excellent electrocatalytic stability. Theory calculations show that the Mn 2 CoO 4 surface has strong interaction with NO 3 –, which can effectively inhibit the occurrence of hydrogen evolution, beneficial for NO 3 – -to-NH 3 conversion.