Rational Design and Validation of Cu₂O/Cu Heterogeneous Interface Catalyst for CO₂ Electroreduction to C₂₊ Products

Rapid construction of highly active non-precious metal catalysts for electrochemical CO₂ reduction reaction (CO₂RR) to C₂₊ products is still challenging. Under the guidance of theoretical calculation, the Cu₂O(200)/Cu(111) is screened heterogeneous catalyst which is favorable for arduous CO₂ activation and unstable ^*CO adsorption during the electrochemical CO₂RR. Then, a novel Cu₂O(200)/Cu(111) heterogeneous interface is fabricated by an ambient precipitation coupled chemical reduction strategy. Notably, the obtained Cu₂O/Cu exhibits excellent activity for CO₂RR, which FE_C2+ is 82.98% under the industrial current density of 450 mA cm^-2 in membrane electrode assembly cell. In situ X-ray photoelectron spectroscopy combined with spherical aberration correction electron microscope reveals Cu₂O/Cu interface exhibits the excellent structural durability. Furthermore, in situ Raman and in situ attenuated total reflection-surface-enhanced IR absorption spectroscopy directly capture ^*COOH, ^*CHO, and ^*COCHO intermediates, disclosing the formation of the C₂₊ products involves in the ^*COCHO pathway. Mechanism studies demonstrate the presence of charge aggregation at Cu₂O/Cu interface directly reduces the energy barrier for C─C coupling (rate-determining step) to 0.76 eV. This work developed a highly active heterogeneous interface for CO₂RR, which provides a novel insight for the fabrication of Cu-based catalysts.