Electrosynthesis of multicarbon products, such as C₂H₄, from CO₂ reduction on copper (Cu) catalysts holds promise for achieving carbon neutrality. However, maintaining a steady high current-level C₂H₄ electrosynthesis still encounters challenges, arising from unstable alkalinity and carbonate precipitation caused by undesired ion migration at the cathode under a repulsive electric field. To address these issues, we propose a universal “charge release” concept by incorporating tiny amounts of an oppositely charged anionic ionomer (e.g., perfluorinated sulfonic acid, PFSA) into a cationic covalent organic framework on the Cu surface (cCOF/PFSA). This strategy effectively releases the hidden positive charge within the cCOF, enhancing surface immobilization of cations to impede both outward migration of generated OH^– and inward migration of cations, inhibiting carbonate precipitation and creating a strong alkaline microenvironment. Meanwhile, the ionomer’s hydrophobic chains create a hydrophobic environment within the cCOF, facilitating efficient gas transport. In situ characterizations and theoretical calculations demonstrate that the cCOF/PFSA catalyst establishes a hydrophobic strong alkaline microenvironment, optimizing the adsorption strength and configuration of *CO intermediates to promote the C₂H₄ formation. The optimized catalyst achieves a 70.5% Faradaic efficiency for C₂H₄ with a partial current density over 470 mA cm^–2. Notably, it delivers a high single-pass carbon efficiency of 96.5% for CO₂RR and sustains an exceptional stability over 760 h. When implemented in a large-area MEA electrolyzer and a 5-cell MEA stack, the system achieves an industrial current of 15 A and continuous C₂H₄ production exceeding 19 mL min^–1, marking a significant step toward industrial feasibility in CO₂RR-to-C₂H₄ conversion.

中文翻译：

---

阴离子离聚物：释放表面固定化阳离子和已建立的疏水微环境，可在一个月内在大电流下高效、持久地进行 CO2 -乙烯电合成


在铜 （Cu） 催化剂上通过 CO₂ 还原电合成多碳产品，例如 C₂H₄，有望实现碳中和。然而，保持稳定的高电流水平 C₂H₄ 电合成仍然面临挑战，这是由于在排斥电场下阴极上不需要的离子迁移引起的不稳定碱度和碳酸盐沉淀引起的。为了解决这些问题，我们提出了一种通用的“电荷释放”概念，方法是将微量带相反电荷的阴离子离聚物（例如，全氟磺酸，PFSA）掺入Cu表面的阳离子共价有机框架（cCOF/PFSA）中。这种策略有效地释放了 cCOF 中隐藏的正电荷，增强了阳离子的表面固定化，以阻止生成的 OH^– 向外迁移和阳离子向内迁移，抑制碳酸盐沉淀并创造强碱性微环境。同时，离聚物的疏水链在 cCOF 内创造了疏水环境，促进了高效的气体运输。原位表征和理论计算表明，cCOF/PFSA 催化剂建立了疏水性强碱性微环境，优化了 *CO 中间体的吸附强度和构型，促进了 C₂H₄ 的形成。优化的催化剂对 C₂H₄ 实现了 70.5% 的法拉第效率，部分电流密度超过 470 mA cm^–2。值得注意的是，它为 CO₂RR 提供了 96.5% 的高单程碳效率，并在 760 小时内保持出色的稳定性。 当在大面积 MEA 电解槽和 5 电池 MEA 堆栈中实施时，该系统可实现 15 A 的工业电流和超过 19 mL min^–1 的连续 C₂H₄ 生产，标志着朝着 CO₂RR 到 C₂H₄ 转化的工业可行性迈出了重要一步。