Self-Polarization Triggered Multiple Polar Units Toward Electrochemical Reduction of CO 2 to Ethanol with High Selectivity

• Published in: Angewandte Chemie International Edition 2023-06, Vol.62 (26), p.e202302241
• Main Authors: Zhang, Yangyang, Chen, Yanxu, Wang, Xiaowen, Feng, Yafei, Zhang, Huaikun, Zhang, Genqiang
• Format: Article
• Language: English
• Subjects: Adsorption; Carbon; Carbon Dioxide; Electricity; Ethanol
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202302241

Electrochemical conversion of CO to highly valuable ethanol has been considered a intriguring strategy for carbon neutruality. However, the slow kinetics of coupling carbon-carbon (C-C) bonds, especially the low selectivity ethanol than ethylene in neutral conditions, is a significant challenge. Herein, the asymmetrical refinement structure with enhanced charge polarization is built in the vertically oriented bimetallic organic frameworks (NiCu-MOF) nanorod array with encapsulated Cu O (Cu O@MOF/CF), which can induce an intensive internal electric field to increase the C-C coupling for producing ethanol in neutral electrolyte. Particularly, when directly employed Cu O@MOF/CF as the self-supporting electrode, the ethanol faradaic efficiency (FE ) could reach maximum 44.3 % with an energy efficiency of 27 % at a low working-potential of -0.615 V versus the reversible hydrogen electrode (vs. RHE) using CO -saturated 0.5 M KHCO as the electrolyte. Experimental and theoretical studies suggest that the polarization of atomically localized electric fields derived from the asymmetric electron distribution can tune the moderate adsorption of *CO to assist the C-C coupling and reduce the formation energy of H CCHO*-to-*OCHCH for the generation of ethanol. Our research offers a reference for the design of highly active and selective electrocatalysts for reducing CO to multicarbon chemicals.