Electrochemical CO₂ reduction is a critical approach to reducing the globally accelerating CO₂ emission and generating value-added products. Despite great efforts to optimize catalyst activity and selectivity, facilitating the catalyst accessibility to high CO₂ concentrations while maintaining electrode durability remains a significant challenge. Here, we designed a catalytic system that mimics the alveolus structure in mammalian lungs with high gas permeability but very low water diffusibility, enabling an array of three-phase catalytic interfaces. Flexible, hydrophobic, nanoporous polyethylene membranes with high gas permeability were used to enable efficient CO₂ access and a high local alkalinity on the catalyst surface at different CO₂ flow rates. Such an alveolus-mimicking structure generates a high CO production Faradaic efficiency of 92% and excellent geometric current densities of CO production (25.5 mA cm⁻²) at −0.6 V versus the reversible hydrogen electrode, with a very thin catalyst thickness of 20−80 nm.

电化学减少CO ₂是减少全球范围内加速CO ₂排放并产生增值产品的关键方法。尽管为优化催化剂活性和选择性做出了巨大努力，但是在保持电极耐用性的同时，促进催化剂易于达到高CO ₂浓度仍然是一个重大挑战。在这里，我们设计了一种催化系统，该系统可以模拟哺乳动物肺中的肺泡结构，具有高的气体渗透性，但水扩散性非常低，因此可以实现一系列三相催化界面。使用具有高透气性的柔性疏水性纳米多孔聚乙烯膜以实现有效的CO ₂在不同的CO ₂流速下，在催化剂表面具有较高的可及性和较高的局部碱度。与可逆氢电极相比，这种可模仿肺泡的结构产生高的CO产生法拉第效率，达到92％，在-0.6 V时产生出色的CO产生的几何电流密度（25.5 mA cm ^-2），催化剂厚度非常薄，仅为20- 80纳米