Redirecting Charge Distribution and Spatial Proximity of Co−O−Cu Motif with 4f−2p−3d Orbital Hybridization for High‐Efficiency Urea Electrosynthesis

Abstract

ABSTRACT Electrocatalytic CO 2 /NO 3 − co‐reduction to access urea typically relies on the tailored two‐site catalysts, with the complexity of C/N‐intermediate generation and C─N coupling that limit urea synthesis efficiency. Here, a 4f (Ce)−2p (O)−3d (Co) orbital hybridization maneuver is demonstrated to customize a spin‐polarized Co‐site and a relatively electron‐rich Cu‐site for generating *NH 2 and *CO species to undergo C─N coupling to access urea, respectively, delivering a production rate of 2612.4 µg mg −1 h −1 at −0.27 V RHE , with an ultrahigh Faradaic efficiency (85.7%). Mechanistic investigations elucidate that the 4f−2p−3d motif enables the high‐spin Co 2+ (t 2g 5 e g 2 ) translation toward low‐spin Co 3+ (t 2g 6 e g 0 ), which enhances the electronic interaction between the e g ‐orbital of Co and 𝜎‐orbital of *NO, favoring *NH 2 formation. Further, the electron‐deficient Co 3+ ‐site formed can act as a localized electron acceptor to manipulate the electron structure of the adjacent Cu‐site, strengthening the hybridization degree between the catalyst's Cu 3d and C 2p of CO 2 to foster *CO generation. Then, interposed Ce narrows the Co─O─Cu distance, which spatially benefits *NH 2 and *CO coupling to form the C─N bond, overall promoting urea synthesis. The synergy of electronic interaction and geometric effect offers a feasible paradigm to precisely customize activity centers for high‐efficiency waste feedstock valorization.