Plasma-Electrochemical Production of Urea from Air and Flue Gas

Industrial urea synthesis is energy-intensive with high CO 2 emissions, while conventional electrochemical urea synthesis is plagued by sluggish C–N coupling kinetics and low selectivity. Herein, we propose a tandem plasma-electrochemical strategy for sustainable and efficient urea synthesis using air and flue gas as abundant feedstocks, which integrates three core steps of plasma-assisted air-to-NO 2 – conversion, electrocatalytic reduction of flue gas-derived CO 2 to HCOOH, as well as electrocatalytic coreduction of NO 2 – and HCOOH to urea. By rationally engineering the catalysts and optimizing the reaction parameters, we achieve an outstanding urea yield rate of 478.5 mmol h –1 g –1 and Faradaic efficiency of 75.8%. This study provides an innovative tandem pathway for urea synthesis through the direct use of industrial flue gas and atmospheric air, thus opening new horizons for green and energy-efficient production of various organonitrogen chemicals.