Ambient ammonia production via electrocatalytic nitrite reduction catalyzed by a CoP nanoarray

Industrial-scale ammonia (NH3) production mainly relies on the energy-intensive and environmentally unfriendly Haber-Bosch process. Such issue can be avoided by electrocatalytic N-2 reduction which however suffers from limited current efficiency and NH3 yield. Herein, we demonstrate ambient NH3 production via electrochemical nitrite (NO2-) reduction catalyzed by a CoP nanoarray on titanium mesh (CoP NA/TM). When tested in 0.1 M PBS (pH = 7) containing 500 ppm NO2-, such CoP NA/TM is capable of affording a large NH3 yield of 2,260.7 +/- 51.5 mu g.h(-1).cm(-2) and a high Faradaic efficiency of 90.0 +/- 2.3% at -0.2 V vs. a reversible hydrogen electrode. Density functional theory calculations reveal that the potential-determining step for NO2- reduction over CoP (112) is *NO2 -> *NO2H.

Automated summary

In this study, ambient ammonia production via electrochemical nitrite (NO2-) reduction catalyzed by a CoP nanoarray on titanium mesh (CoP NA/TM) is demonstrated. The catalyst showed a high NH3 yield and Faradaic efficiency in alkaline solution, presenting a potential alternative to industrial ammonia production.