Electrochemical CO₂ reduction to multi-carbon fuels and chemicals is intriguing but remains a challenge. Here, we report that a combination of Sn doping and creation of oxygen vacancies (V_O) can synergistically boost CO₂ reduction to C₂H₄ over CuO nanosheets with an onset potential of −0.7 V (versus reversible hydrogen electrode). The activity and selectivity of CuO can be easily tuned by manipulation of Sn dopant and V_O contents. The Faradaic efficiency toward C₂H₄ formation over Sn-doped CuO(V_O) approaches 48.5% ± 1.2%, which maintains stability over 24 h at a mild overpotential, in contrast to a maximum of 26.8% ± 2.2% over pristine CuO. The Sn-doped CuO(V_O) catalyst presents an approximately 2.3-fold improvement in C₂H₄ current compared to undoped CuO at similar overpotentials. Theoretical calculations further show that doping of Vo-enriched CuO surface by Sn lowers the dimerization energy of adsorbed CO intermediate, thereby promoting C–C coupling to yield C₂H₄.

用电化学方法将CO ₂还原为多碳燃料和化学物质虽然很吸引人，但仍然是一个挑战。在这里，我们报道，Sn掺杂和氧空位（V _O）的组合可以协同将Cu 2纳米片上的CO ₂还原效率提高到C ₂ H ₄，起始电位为-0.7 V（相对于可逆氢电极）。通过控制Sn掺杂剂和V _O的含量，可以轻松地调节CuO的活性和选择性。Sn掺杂CuO（V _O）对C ₂ H ₄形成的法拉第效率）接近48.5％±1.2％，在温和的超电势下可在24小时内保持稳定性，相比之下，原始CuO的最大值为26.8％±2.2％。与未掺杂的CuO在相似的超电势下相比，掺Sn的CuO（V _O）催化剂的C ₂ H ₄电流提高了约2.3倍。理论计算进一步表明，用Sn掺杂富Vo的CuO表面会降低吸附的CO中间体的二聚能，从而促进C–C偶联生成C ₂ H ₄。