Low‐Voltage Driven Co‐Production of Ammonia, Formate, and Hydrogen From Nitrite Reduction Coupled Formaldehyde Oxidation System on Ultra‐Stable AuCuRh Nanowires under Illumination

Abstract The nitrite electroreduction reaction (NO 2 RR) offers a green and sustainable pathway for environmental wastewater treatment and ammonia (NH 3 ) generation. Herein, defect‐rich trimetallic AuCuRh nanowires (AuCuRh NWs) with a large number of grain boundaries, twin boundaries, and atomic steps are successfully synthesized by galvanic replacement reaction. Due to its self‐stability and high activity, AuCuRh NWs can efficiently drive the stable NO 2 RR at 0 V potential (Faradaic efficiency: 98.32%, NH 3 yield rate: 20.49 mg h −1 mg cat −1 ). Moreover, AuCuRh NWs also reveal excellent electrocatalytic activity for the formaldehyde electrooxidation reaction (FOR), which can reach 10 mA cm −2 at only 0.35 V potential. The NO 2 RR||FOR electrolysis system assembled with AuCuRh NWs requires only the electrolysis voltage of 0.38 V to achieve the co‐production of NH 3 , formate, and hydrogen and ultra‐stable continuous electrolysis for 300 hours. The NO 2 RR||FOR electrolysis system can be further decreased to only 0.29 V under illumination due to plasmon‐enhanced activity. This study provides an energy‐efficient coupling strategy for the stable co‐production of value‐added chemicals.