Copper Atom Pairs Stabilize OCCO Dipole Toward Highly Selective CO 2 Electroreduction to C 2 H 4

Deeply electrolytic reduction of carbon dioxide (CO ) to high-value ethylene (C H ) is very attractive. However, the sluggish kinetics of C-C coupling seriously results in the low selectivity of CO electroreduction to C H . 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 H production. The C H faradaic efficiency (FE) reaches 51 % with a current density of 469.4 mA cm , much superior to the Cu single site catalyst (Cu SAC) (~0 %). Moreover, the Cu2 catalyst has a higher turnover frequency (TOF, ~520 h ) compared to Cu nanoparticles (~9.42 h ) and Cu SAC (~0.87 h ). 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 H .