Polymer Modification Strategy to Modulate Reaction Microenvironment for Enhanced CO2 Electroreduction to Ethylene

Abstract Modulation of the microenvironment on the electrode surface is one of the effective means to improve the efficiency of electrocatalytic carbon dioxide reduction (eCO 2 RR). To achieve high conversion rates, the phase boundary at the electrode surface should be finely controlled to overcome the limitation of CO 2 solubility in the aqueous electrolyte. Herein, we developed a simple and efficient method to structure electrocatalyst with a superhydrophobic surface microenvironment by one‐step co‐electrodeposition of Cu and polytetrafluoroethylene (PTFE) on carbon paper. The super‐hydrophobic Cu‐based electrode displayed a high ethylene (C 2 H 4 ) selectivity with a Faraday efficiency (FE) of 67.3 % at −1.25 V vs. reversible hydrogen electrode (RHE) in an H‐type cell, which is 2.5 times higher than a regular Cu electrode without PTFE. By using PTFE as a surface modifier, the activity of eCO 2 RR is enhanced and water (proton) adsorption is inhibited. This strategy has the potential to be applied to other gas‐conversion electrocatalysts.