Reversible Breathing of Cu─Co Dual‐Atom Sites Enables Spatially Proximal C─N Coupling for Urea Electrosynthesis

ABSTRACT Electrocatalytic urea synthesis via the Langmuir–Hinshelwood pathway demands spatially proximal active sites to synchronize the generation and cross‐coupling of C‐ and N‐derived intermediates. Heteronuclear dual‐atom catalysts offer chemically differentiated sites for this purpose, yet whether their bimetallic centers remain static or dynamically evolve during C─N coupling remains unresolved. Here, we construct a well‐defined N 3 ─Cu─Co─N 3 dual‐atom site for the electrochemical coreduction of CO 2 and NO 3 − to synthesize urea and uncover its reversible, electric‐field‐driven structural breathing under electrocatalytic conditions, affording a maximum urea yield rate of 4828.4 ± 136.5 µg h −1 mg cat −1 and a Faradaic efficiency of 56.8 ± 7.6% at −1.2 V (vs. RHE). Operando x‐ray absorption spectroscopy (XAS) revealed a reversible, electric‐field‐driven breathing‐like modulation of the Cu─Co distance, characterized by Cu─Co contraction and Cu─N/Co─N elongation. Density functional theory (DFT) calculations show that the Cu─Co distance reaches a minimum of 2.16 Å in the *CONH 2 ‐bound configuration formed during the initial C─N coupling step. The adaptive contraction brings C‐ and N‐intermediates into close proximity to enable C─N coupling, thereby reconfiguring heteronuclear dual‐atom sites from static pairs into dynamically responsive centers and highlighting field‐tunable metal–metal distance as a catalytic design lever.