Urea
(CO(NH2)2) is the most common
nitrogen
fertilizer that is promoting food production worldwide due to its
high nitrogen content. However, the conventional urea synthesis involving
hydrogenolysis of nitrogen and C–N bond coupling requires harsh
conditions and a massive carbon footprint. Herein, we report a promising
technology for the green synthesis of urea using nitrate (NO3
–) and carbon dioxide (CO2) under ambient
conditions over Ru/Pt/Pd-modified three-dimensional copper foam (Ru/Pt/Pd-Cu
CF) electrode. The Ru-Cu CF catalyst delivers a high urea yield of
151.6 μg h–1 cm–2 at a low
onset potential of −0.3 V vs Ag/AgCl (0.13 V vs RHE) as well
as an FE of 25.4%, surpassing that of Pt/Pd-Cu CF. Moreover, it is
confirmed by operando electrocatalytic Raman spectroscopy
and theoretical calculations that the *COOH intermediate is the rate-determining
step of C–N bond coupling. Benefiting from the partial 3d states
of surface Ru sites, the Ru-Cu CF electrode possesses the lowest formation
energy of the *COOH intermediate to accelerate the urea synthesis.
This work provides an extraordinarily sustainable strategy for green
urea synthesis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.