Electrochemical carbon dioxide (CO₂) reduction powered by renewable energy source is a promising strategy for the sustainable carbon cycle, while the selectivity toward C₂₊ products is still a great challenge. Herein, a novel stepped cuprous oxide catalyst with abundant Cu vacancies (Cu_v-Cu₂O catalyst) is developed to enhance the selectivity and efficiency of CO₂ conversion toward C₂ products. This catalyst exhibits high C₂H₄ partial current density and production rate at a low overpotential benefiting from the stepped surface and the modified electronic structure by Cu vacancies. Furthermore, density functional theory calculations demonstrate that the Cu vacancy-enriched Cu₂O surface ensures strong adsorption to *COH but weak affinities to *CO and *CH₂ intermediates, which promotes CO₂ electroreduction to C₂H₄ products. The enhanced selectivity of C₂H₄, accompanied with the Cu vacancies and Cu⁺ species, can remain stable during the long-term test. This study will provide guidance on designing efficient electrocatalysts for CO₂ reduction towards hydrocarbon products.

由可再生能源驱动的减少电化学二氧化碳（CO ₂）是可持续碳循环的一种有前途的策略，而对C ₂₊产品的选择性仍然是一个巨大的挑战。本文中，开发了具有大量Cu空位的新型阶梯式氧化亚铜催化剂（Cu _v -Cu ₂ O催化剂），以提高CO ₂向C ₂产物转化的选择性和效率。该催化剂显示出高C ₂ H ₄阶梯状的表面和铜空位对电子结构的影响，使低电位下的部分电流密度和生产率得以提高。此外，密度泛函理论计算表明，富集Cu空位的Cu ₂ O表面可确保对* COH的强烈吸附，但对* CO和* CH ₂中间体的亲和力较弱，从而促进了CO ₂电还原为C ₂ H ₄产物。在长期测试中，C ₂ H ₄选择性的增强以及铜的空位和Cu ^+的种类可以保持稳定。这项研究将为设计高效的CO ₂电催化剂提供指导 减少碳氢化合物产品。