69. Photoelectrocatalytic Synthesis of Urea from Carbon Dioxide and Nitrate over a Cu2O Photocathode

Min Li, Qiujin Shi, Zhenhua Li, Ming Xu, Shixin Yu, Ye Wang, Si-Min Xu, Haohong Duan*
Angew. Chem. Int. Ed. 2024, e202406515
DOI: 10.1002/anie.202406515

Abstract
Transformation of carbon dioxide and nitrate ions into ureaoffers an attractive route for both nitrogen fertilizer production andenvironmental remediation. However, achieving this transformationunder mild conditions remains challenging. Herein, we report anefficient photoelectrochemical method for urea synthesis by coreductionof carbon dioxide and nitrate ion over a Cu2O photocathode,delivering urea formation rate of 29.71±2.20 μmol g−1 h−1 and Faradaicefficiency (FE) of 12.90±1.15 % at low external potential (−0.017 V vs.reversible hydrogen electrode). Experimental data combined withtheoretical calculations suggest that the adsorbed CO* and NO2*species are the key intermediates, and associated C−N coupling isthe rate-determining step. This work demonstrates that Cu2O is anefficient catalyst to drive co-reduction of CO2 and NO3− to urea underlight irradiation with low external potential, showing great opportunityof photoelectrocatalysis as a sustainable tool for value-addedchemical synthesis.