Electrocatalytic conversion of carbon monoxide (CO) is being actively developed as a key component for tandem CO₂ electrolysis. Great effort has been devoted to engineering CO reduction electrocatalysts for better multicarbon product selectivity. However, less work has focused on other performance parameters that are crucial for commercializing CO electrolysis, such as liquid product concentration and purity. Here, we present an internally coupled purification strategy to substantially improve the acetate concentration and purity in CO electrolysis. This strategy utilizes an alkaline-stable anion exchange membrane with high ethanol permeability and a selective ethanol partial oxidation anode to control the CO reduction product stream. We demonstrate stable 120-h continuous operation of the CO electrolyser at a current density of 200 mA cm⁻² and a full-cell potential of <2.3 V, continuously producing a 1.9 M acetate product stream with a purity of 97.7%. The acetate stream was further improved to a concentration of 7.6 M at >99% purity by tuning the reaction conditions. Finally, a techno-economic analysis shows that a highly concentrated liquid product stream is essential to reduce the energy consumption of product separation.

正在积极开发一氧化碳 (CO) 的电催化转化作为串联 CO _{2的关键成分}电解。为了提高多碳产物的选择性，人们一直致力于设计 CO 还原电催化剂。然而，较少的工作集中在对 CO 电解商业化至关重要的其他性能参数上，例如液体产品浓度和纯度。在这里，我们提出了一种内部耦合纯化策略，以显着提高 CO 电解中的乙酸盐浓度和纯度。该策略利用具有高乙醇渗透性的碱性稳定阴离子交换膜和选择性乙醇部分氧化阳极来控制 CO 还原产物流。^{我们展示了 CO 电解器在 200 mA cm -2}的电流密度下稳定的 120 小时连续运行和 <2.3 V 的全电池电位，连续生产 1.9 M 醋酸盐产品流，纯度为 97.7%。通过调整反应条件，乙酸盐流进一步提高到 7.6 M 的浓度，纯度 >99%。最后，技术经济分析表明，高度浓缩的液体产品流对于降低产品分离的能耗至关重要。