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

ABSTRACT

Deeply electrolytic reduction of carbon dioxide (CO2) to high-value ethylene (C2H4) is very attractive. However, the sluggish kinetics of C-C coupling seriously results in the low selectivity of CO2 electroreduction to C2H4. 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 C2H4 production. The C2H4 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 C2H4.