The electrochemical reduction of CO₂ to ethylene has the potential to reduce greenhouse gas emissions while producing commodity chemicals for plastics; however, a scalable and feasible system for this remains a challenge. Herein, we report an efficient and stackable electrode design for the electrolysis of CO₂ to ethylene. Using KOH-incorporated Cu nanoparticle (Cu-KOH) as the cathode in a zero-gap electrolyzer, Faradaic efficiency of 78.7% for C₂ products was achieved at a current density of 281 mA cm^–2. Among C₂ products, ethylene with a 54.5% FE was dominant product. For mass production, three membrane electrode assemblies (MEAs) were stacked and operated. Operando X-ray absorption spectroscopy under the zero-gap electrolyzer suggested mainly metallic Cu state with some persistent oxide-derived Cu species in Cu-KOH, including Cu₂O and Cu(OH)₂, which expected a synergistic effect for the conversion of CO₂ to C₂H₄. Our findings provide a new strategy for converting CO₂ to C₂H₄, which is expected to accelerate the commercialization of high-value chemical production through electrochemical CO₂ reduction.

通过电化学方式将CO ₂还原为乙烯，有可能减少温室气体排放，同时生产用于塑料的商品化学品。但是，一个可扩展且可行的系统仍然是一个挑战。在此，我们报道了一种用于将CO ₂电解为乙烯的有效且可堆叠的电极设计。在零间隙电解槽中，使用掺有KOH的Cu纳米粒子（Cu-KOH）作为阴极，在281 mA cm ^–2的电流密度下，C ₂产品的法拉第效率达到了78.7％。在C ₂产品中，具有54.5％FE的乙烯是主要产品。为了批量生产，将三个膜电极组件（MEA）堆叠并操作。Operando零间隙电解槽下的X射线吸收光谱表明，Cu-KOH中主要为金属Cu态，并存在一些持久性氧化物衍生的Cu物种，包括Cu ₂ O和Cu（OH）₂，这有望为CO的转化产生协同效应。₂至C ₂ H ₄。我们的发现提供了将CO ₂转化为C ₂ H ₄的新策略，有望通过电化学还原CO ₂来加速高价值化学生产的商业化。