High-efficiency NO electroreduction to NH over honeycomb carbon nanofiber at ambient conditions.

Electrocatalytic NO reduction is a promising technology for ambient NO removal with simultaneous production of highly value-added NH. Herein, we report that honeycomb carbon nanofiber coated on carbon paper acts as an efficient metal-free catalyst for ambient electroreduction of NO to NH. In 0.2 M NaSO solution, such catalyst achieves an NH yield of 22.35 μmol h cm with a high Faradaic efficiency of up to 88.33%. Impressively, it also shows excellent stability for 10-h continuous electrolysis. Theoretical calculations reveal that the most active center of functional groups is -OH group for NO reduction with a low energy barrier (ΔG of 0.29 eV) for the potential-determining step (*NO + H → *HNO).