Copper Atom Pairs Stabilize *OCCO Dipole Toward Highly Selective CO2 Electroreduction to C2H4

Abstract Deeply electrolytic reduction of carbon dioxide (CO 2 ) to high‐value ethylene (C 2 H 4 ) is very attractive. However, the sluggish kinetics of C−C coupling seriously results in the low selectivity of CO 2 electroreduction to C 2 H 4 . Herein, we report a copper‐based polyhedron (Cu2) that features uniformly distributed and atomically precise bi‐Cu units, which can stabilize *OCCO dipole to facilitate the C−C coupling for high selective C 2 H 4 production. The C 2 H 4 faradaic efficiency (FE) reaches 51 % with a current density of 469.4 mA cm −2 , much superior to the Cu single site catalyst (Cu SAC) (~0 %). Moreover, the Cu2 catalyst has a higher turnover frequency (TOF, ~520 h −1 ) compared to Cu nanoparticles (~9.42 h −1 ) and Cu SAC (~0.87 h −1 ). In situ characterizations and theoretical calculations revealed that the unique Cu2 structural configuration could optimize the dipole moments and stabilize the *OCCO adsorbate to promote the generation of C 2 H 4 .