Electrochemical reduction of carbon monoxide to high-value multi-carbon (C₂₊) products offers an appealing route to store sustainable energy and make use of the chief greenhouse gas leading to climate change, i.e., CO₂. Among potential products, C₂₊ liquid products such as ethanol are of particular interest owing to their high energy density and industrial relevance. In this work, we demonstrate that Ag-modified oxide-derive Cu catalysts prepared via high-energy ball milling exhibit near 80% Faradaic efficiencies for C₂₊ liquid products at commercially relevant current densities (>100 mA cm⁻²) in the CO electroreduction in a microfluidic flow cell. Such performance is retained in an over 100-hour electrolysis in a 100 cm² membrane electrode assembly (MEA) electrolyzer. A method based on surface-enhanced infrared absorption spectroscopy is developed to characterize the CO binding strength on the catalyst surface. The lower C and O affinities of the Cu–Ag interfacial sites in the prepared catalysts are proposed to be responsible for the enhanced selectivity for C₂₊ oxygenates, which is the experimental verification of recent computational predictions.

将一氧化碳电化学还原为高价值的多碳 (C ₂₊ ) 产品，为储存可持续能源和利用导致气候变化的主要温室气体（即 CO _{2 ）}提供了一条极具吸引力的途径。在潜在产品中，C ₂₊液体产品（例如乙醇）因其高能量密度和工业相关性而受到特别关注。在这项工作中，我们证明了通过高能球磨制备的 Ag 改性氧化物衍生 Cu 催化剂在商业相关电流密度（>100 mA cm ^{-2）下对 C} ₂₊液体产品表现出接近 80% 的法拉第效率) 在微流体流动池中的 CO 电还原中。这种性能在 100 cm ²膜电极组件 (MEA) 电解槽中经过 100 多个小时的电解后仍保持不变。开发了一种基于表面增强红外吸收光谱的方法来表征催化剂表面的 CO 结合强度。所制备催化剂中 Cu-Ag 界面位点较低的 C 和 O 亲和力被认为是提高 C ₂₊含氧化合物选择性的原因，这是最近计算预测的实验验证。