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 (NO3-) provides us a sustainable and environmentally friendly alternative to the traditional Haber-Bosch process. In this work, Mn2CoO4 nanoarray grown on carbon cloth (Mn2CoO4/CC) serves as a superior electrocatalyst for efficient NH3 synthesis by selective reduction of NO3-. When operated in 0.1 M PBS with 0.1 M NaNO3, Mn2CoO4/CC reaches a high Faraday efficiency of 98.6% and a large NH3 yield up to 11.19 mg/h/cm2. Moreover, it exhibits excellent electrocatalytic stability. Theory calculations show that the Mn2CoO4 surface has strong interaction with NO3-, which can effectively inhibit the occurrence of hydrogen evolution, beneficial for NO3--to-NH3 conversion.