Efficient nitrate electroreduction over Mn-doped Cu catalyst via regulating N-containing intermediates adsorption configuration

The electrochemical reduction of NO₃⁻ to NH₃ holds promise for economic and environmental benefits, presenting an energy-efficient alternative to the traditional Haber–Bosch method. However, challenges exist due to its sluggish kinetics, multiple intermediates, and various reaction pathways. In this study, Mn-doped-Cu catalyst was synthesized and employed for electrochemical NO₃⁻-to-NH₃ conversion. The doping of Mn into Cu resulted in exceptional performance, achieving a FE of 95.8% and an NH₃ yield rate of 0.91 mol g⁻¹ h⁻¹ at −0.6 V in a neutral electrolyte at low NO₃⁻ concentration. Detailed experimental studies and theoretical calculations revealed that the Mn dopant enhanced the kinetic rate of NO₂⁻-to-NH₃ and induced a distinct configuration of *NO. This alteration decreased the energy barrier of *NO-to-*NOH, consequently promoting the conversion of NO₃⁻-to-NH₃.