Plasma-electrocatalytic synthesis of urea from air and CO2

Electrochemical C-N coupling of CO2 with nitrogenous sources (e.g., N2, NO3−) provides a promising method for urea production, whereas the current electrochemical methods are limited by low conversion efficiency or reliance on fossil fuel-derived NO3− feedstock. Here, we develop a plasma-electrocatalytic route for urea synthesis from ambient air and CO2, which starts with plasma-assisted air activation to generate reactive NOx− (92.1% NO2−), followed by electrocatalytic co-reduction of CO2 + NOx− to urea. By using a single-atom Ru1/CuOx catalyst in double chamber membrane electrode assembly, we achieve a urea yield rate of 106.9 mmol h−1 gcat−1 and a Faradaic efficiency of 86.7%. This plasma-electrocatalytic route demonstrates a paradigm-shifting strategy for revolutionizing urea synthesis, making a great leap toward decarbonized nitrogen economy. Current urea synthesis methods are challenged by low C-N coupling efficiency or reliance on fossil fuel-derived NH3/NO3−. Here, the authors report plasma-electrocatalytic synthesis of urea from air and CO2, which enables a high-efficiency C-N coupling and circumvents fossil fuel dependency.