Tailoring electronic structure of copper nanosheets by silver doping toward highly efficient electrochemical reduction of nitrogen to ammonia

Electrochemical nitrogen reduction reaction (NRR) at ambient conditions is a highly attractive route for ammonia (NH3) synthesis. However, the NRR suffers from low NH3 yield and Faradaic efficiency (FE) due to the lack of effective electrocatalyst. Here Ag-doped Cu nanosheets grown on carbon paper (Ag-CuNS/CP) have been synthesized and utilized as efficient electrocatalysts for NRR. The doping of Ag leads to the formation of electron-deficient Cu atoms in Ag-CuNS/CP, which can suppress hydrogen evolution reaction and enhance N2 adsorption in neutral media, leading to enhanced NRR activity. In 0.1 M Na2SO4 electrolyte, the Ag-CuNS/CP catalyst exhibits a high FE of 20.9% with a NH3 yield rate of 61.5 µg h−1 mg-1cat. at −0.4 V versus the reversible hydrogen electrode. This study offers a simple but effective approach to design highly active and selective NRR electrocatalysts for NH3 synthesis.