Membrane‐electrode assembly (MEA)‐based CO electrolysis (COE) has demonstrated the capability to produce C2+ products with high faradaic efficiency at ampere‐level current densities. However, most studies on COE have achieved performance benchmarks under strongly alkaline conditions (e.g., ≥1 M KOH, pH ≥ 14), raising the question of whether such high pH levels are essential for optimal performance. In this study, we investigated the effects of different electrolytes (KHCO3, K2CO3, and KOH) on MEA‐based CO electrolysis, focusing on the influence of pH and the impact of anodic oxidation on the selectivity of various liquid products. By adjusting electrolyte concentration and pH, we achieved significant partial current densities for ethanol (189 ± 5 mA cm‐2) and propanol (89 ± 4 mA cm‐2) using 0.5 M K2CO3. This high performance is attributed to the creation of a moderate local alkaline environment and the relatively high resistance to anodic oxidation. Additionally, durability measurements emphasized the critical importance of eliminating anodic oxidation to optimize MEA‐based COE for ethanol and propanol production.

中文翻译：

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膜-电极-组装 CO 电解中的电解质效应


基于膜电极组件 （MEA） 的 CO 电解 （COE） 已证明能够在安培级电流密度下生产具有高法拉第效率的 C2+ 产物。然而，大多数关于 COE 的研究都在强碱性条件下（例如，≥1 M KOH，pH ≥ 14）达到了性能基准，这提出了一个问题，即如此高的 pH 值是否对于最佳性能至关重要。在这项研究中，我们研究了不同电解质 （KHCO3、K2CO3 和 KOH） 对 MEA 基 CO 电解的影响，重点关注 pH 值的影响和阳极氧化对各种液体产物选择性的影响。通过调整电解质浓度和 pH 值，我们使用 0.5 M K2 CO3 实现了乙醇 （189 ± 5 mA cm-2） 和丙醇 （89 ± 4 mA cm-2） 的显着部分电流密度。这种高性能归因于形成适度的局部碱性环境和相对较高的抗阳极氧化性。此外，耐久性测量强调了消除阳极氧化对于优化乙醇和丙醇生产的基于 MEA 的 COE 的至关重要性。