Tailoring the catalytic microenvironment of CuO with hydrophobic CuSA 2 for selective CO 2 electroreduction to C 2+products

Advancing the Faraday efficiency (FE) and current density of Cu catalyzed electrochemical CO 2 reduction (ECR) reaction to produce C 2+ products is important for its practical applications. Constructing a hydrophobic interface to regulate the local reaction environment is an effective method to improve the selectivity of C 2+ products, but it is limited by the low reaction current density. In this work, we fabricated a novel hydrophobic and ECR active copper stearate (CuSA 2 ) decorated CuO nanoparticle catalyst (CuO/CuSA 2 ) for ECR reaction toward C 2+ products. As a result, the CuO/CuSA 2 catalyst achieved an FE of 61.33 % and a partial current density of 429.33 mA cm - 2 for C 2+ products. The CuSA 2 and CuO nanoparticle cooperate very well for the formation of C 2+ products. The in -situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) and electrochemical adsorption experiment indicated that the hydrophobic CuSA 2 regulated the local ECR reaction environment. The local *CO . - 2 and *CO adsorption were strengthened by hydrophobic CuSA 2 modification while the H 2 O adsorption was inhibited. CuO nanoparticle promotes *CO coupling reaction and enhances C 2 intermediates (*OCCOH and *OC 2 H 5 ) adsorption. Hydrophobic CuSA 2 and CuO nanoparticle synergistically promote the generation of C 2+ products. This work provides new insights into the design of hydrophobic CO 2 reduction electrocatalysts for the preparation of C 2+ products.