LAUSR

Industrial Haber-Bosch process for ammonia (NH3) synthesis is extremely important in modern society, however, energy intensive and severe pollution have motivated new eco-friendly NH3 synthesis research. Electroreduction of contaminant nitrate ions back to NH3 is an effective complement, but still limited by low NH3 yield rate and NO3--to-NH3 selectivity. Herein, we report electrochemical nitrate reduction reaction (NTRR) employing single atom Cu catalyst. Atomically dispersed Cu sites anchored on dual-mesoporous N-doped carbon framework display excellent NTRR performance with NH3 yield rate of 13.8 molNH3 gcat.-1 h-1 and NO3--to-NH3 Faradaic efficiency (FE) of 95.5% at -1.0 V. Cu-N-C catalyst can sustain continuous 120 h NTRR test in the simulated NH3 synthesis scenarios with large current density (about 200 mA cm-2) and amplified volume of NO3- solution (9 times). Theoretical calculations reveal that atomically dispersed Cu1-N4 sites reduce the energy barrier of potential-determining step in NTRR and promote the decomposition of primary intermediate in NO3--to-N2 process. These findings provide a guideline for the rational design of highly active, selective and durable electrocatalyst in NTRR.