Chloride Ion Adsorption Enables Ampere‐Level CO2 Electroreduction over Silver Hollow Fiber

• Published in: Angewandte Chemie International Edition 2022-10, Vol.61 (42), p.e202210432-n/a
• Main Authors: Li, Shoujie, Dong, Xiao, Zhao, Yonghui, Mao, Jianing, Chen, Wei, Chen, Aohui, Song, Yanfang, Li, Guihua, Jiang, Zheng, Wei, Wei, Sun, Yuhan
• Format: Article
• Language: English
• Subjects: Adsorption; Ag Hollow Fiber; Ampere-Level; Carbon dioxide; Chloride Ion Adsorption; Chloride ions; CO2 Electroreduction; Coordination; Current density; Density functional theory; Electrocatalysts; Electrochemistry; Electrowinning; Hydrogen evolution reactions; Ion adsorption; Potassium chloride; Silver
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202210432

Electrochemical conversion of CO2 into valuable feedstocks is a promising strategy for carbon neutrality. However, it remains a challenge to possess a large current density, a high faradaic efficiency and excellent stability for practical applications of CO2 utilization. Herein, we report a facile tactic that enables exceedingly efficient CO2 electroreduction to CO by virtue of low‐coordination chloride ion (Cl−) adsorption on a silver hollow fiber (Ag HF) electrode. A CO faradaic efficiency of 92.3 % at a current density of one ampere per square centimeter (1 A cm−2) in 3.0 M KCl with a sustained performance observed during a 150‐hour test was achieved, which is better than state‐of‐the‐art electrocatalysts. The electrochemical results and density functional theory (DFT) calculations suggested a low‐coordination Cl− adsorption on surface of Ag HF, which not only suppressed the competitive hydrogen evolution reaction (HER), but also facilitated the CO2 reduction kinetics. The low‐coordination adsorbed Cl− on the surface of silver hollow fiber (Ag HF) not only suppress the competing hydrogen evolution reaction but also optimizes the kinetics of CO2 reduction to CO at ampere‐level current density.