High-efficiency NO electroreduction to NH3 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 NH3. Herein, we report that honeycomb carbon nanofiber coated on carbon paper acts as an efficient metal-free catalyst for ambient electroreduction of NO to NH3. In 0.2 M Na2SO4 solution, such catalyst achieves an NH3 yield of 22.35 μmol h-1 cm-2 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).