A Copper-Zinc Cyanamide Solid-Solution Catalyst with Tailored Surface Electrostatic Potentials Promotes Asymmetric N-Intermediate Adsorption in Nitrite Electroreduction.

The electrocatalytic nitrite reduction (NO(2)RR) converts nitrogen-containing pollutants to high-value ammonia (NH(3)) under ambient conditions. However, its multiple intermediates and multielectron coupled proton transfer process lead to low activity and NH(3) selectivity for the existing electrocatalysts. Herein, we synthesize a solid-solution copper-zinc cyanamide (Cu(0.8)Zn(0.2)NCN) with localized structure distortion and tailored surface electrostatic potential, allowing for the asymmetric binding of NO(2)(-). It exhibits outstanding NO(2)RR performance with a Faradaic efficiency of ∼100% and an NH(3) yield of 22 mg h(-1) cm(-2), among the best for such a process. Theoretical calculations and in situ spectroscopic measurements demonstrate that Cu-Zn sites coordinated with linear polarized [NCN](2-) could transform symmetric [Cu-O-N-O-Cu] in CuNCN-NO(2)(-) to a [Cu-N-O-Zn] asymmetric configuration in Cu(0.8)Zn(0.2)NCN-NO(2)(-), thus enhancing adsorption and bond cleavage. A paired electro-refinery with the Cu(0.8)Zn(0.2)NCN cathode reaches 2000 mA cm(-2) at 2.36 V and remains fully operational at industrial-level 400 mA cm(-2) for >140 h with a NH(3) production rate of ∼30 mg(NH3) h(-1) cm(-2). Our work opens a new avenue of tailoring surface electrostatic potentials using a solid-solution strategy for advanced electrocatalysis.