CO2 electrolysis to value‐added chemicals and fuels shows tremendous potential to store renewable electricity. It features with H2O as the hydrogen source of CO2 electroreduction. Here, we aim at the effect of the hydrophobicity‐tuned catalyst microenvironment in gas diffusion electrode (GDE) on boosting CO2 electrolysis. The hydrophobic polytetrafluoroethylene (PTFE) nanoparticles are introduced in the Sn catalyst layer of GDE. The PTFE‐modified GDE compared to the non‐PTFE electrode delivers a higher HCOOH Faraday efficiency and lower overpotential at current densities of 50–250 mA cm−2. A two‐dimensional axisymmetric model jointly with electrochemical impedance spectroscopy is developed to provide mechanistic insights into the hydrophobicity regulation. The simulated polarization current densities are in keeping with experimental results. The boosted CO2 electrolysis is attributed to the decrease of the distance from the gas–liquid phase boundary to the electrocatalyst. The understanding of the catalyst microenvironment established here can be generalized to other gas‐involved electrocatalytic reactions.

中文翻译：

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深入了解气体扩散电极中疏水性调节的催化剂微环境以促进二氧化碳电解

一氧化碳2电解生产增值化学品和燃料显示出储存可再生电力的巨大潜力。它的特点是具有H2O作为CO的氢源2电还原。在这里，我们的目标是气体扩散电极（GDE）中疏水性调节的催化剂微环境对提高 CO2 的影响2电解。GDE 的 Sn 催化剂层中引入了疏水性聚四氟乙烯 (PTFE) 纳米颗粒。与非 PTFE 电极相比，PTFE 改性 GDE 在 50-250 mA cm 的电流密度下具有更高的 HCOOH 法拉第效率和更低的过电势−2。开发了与电化学阻抗谱相结合的二维轴对称模型，以提供疏水性调节的机制见解。模拟的极化电流密度与实验结果一致。增加的CO2电解归因于气液相边界到电催化剂的距离的减小。对此处建立的催化剂微环境的理解可以推广到其他涉及气体的电催化反应。