Electrochemical reduction of carbon dioxide (CO₂RR) is an attractive approach toward converting CO₂ to solar fuels. Novel catalyst chemistries and morphologies may provide high selectivity to both one-carbon (C1) and two-carbon (C2) products over hydrogen; however, the limited aqueous solubility of CO₂ restricts the CO₂RR current density. Here, we demonstrate how gasphilic bubble-trap surfaces enhance mass transfer and enrich and maintain CO₂ concentration during CO₂RR by forming a catalyst-proximal plastron layer, consequently increasing the CO₂RR activity on both smooth and nanostructured copper as compared to the conventional headspace or bubbling modes of CO₂ delivery. The H₂ Faradaic efficiency is suppressed from 33% to 13% on smooth copper and from 62% to 33% on nanostructured copper, accompanied by enhanced formation of C2+ products, including ethylene, propanol, and ethanol, and >1% acetone and acetate. We highlight the importance of the catalyst-proximal plastron approach by comparing against recent aqueous-phase CO₂RR studies.

二氧化碳的电化学还原（CO ₂ RR）是将CO ₂转化为太阳能的一种有吸引力的方法。新型的催化剂化学和形态可以提供对氢一碳（C1）和二碳（C2）产物的高选择性。然而，有限的CO ₂水溶性限制了CO ₂ RR电流密度。在这里，我们演示了通过形成催化剂近侧的塑料层，从而提高了CO _2的亲气性气泡捕集表面如何在CO ₂ RR期间增强传质，富集并维持CO ₂浓度。与传统的顶部空间或冒泡的CO ₂输送方式相比，对光滑和纳米结构铜的RR活性。H ₂法拉第效率在光滑铜上从33％抑制到13％，在纳米结构铜上从62％抑制到33％，同时增强了C2 +产物的形成，包括乙烯，丙醇和乙醇，以及> 1％的丙酮和乙酸盐。通过与最近的水相CO ₂ RR研究进行比较，我们强调了催化剂邻近型塑料的方法的重要性。