Effective Utilization of Low NO Concentration for the Electrochemical Synthesis of NH₃

Electrochemical NO reduction (NORR) offers a fascinating alternative to both hazardous NO mitigation and green NH3 production. However, it suffers from a high NO concentration and low NH3 selectivity. Herein, we propose an alternative route for NH3 synthesis from NO exhaust by using an Fe(II)EDTA-NO complexing solution as an electrolyte to couple the complexing absorption denitrification and NORR. A highly efficient NiCoP nanocone array supported on a Ni foam (NiCoP-NCAs/NF) electrocatalyst is designed and prepared for the electrochemical reduction of Fe(II)EDTA-NO. NiCoP-NCAs/NF exhibits a high NH3 yield rate of 0.135 mmol·cm–2·h–1 and a high faradaic efficiency of up to 92.2% at −1.05 V versus the reversible hydrogen electrode. The electrolyte after electroreduction could be used directly for the absorption of low concentrations of NO with a high absorption rate of 100%. The present work provides an alternative approach for the utilization of industrial NO exhaust and sustainable NH3 synthesis.