Regulated Cu Diatomic Distance Promoting Carbon-Carbon Coupling During CO 2 Electroreduction

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2025-01, Vol.21 (2), p.e2406605
• Main Authors: Guan, Hongxin, Zhang, Yuxiang, Fan, Wenjun, Yang, Kang, Li, Guang, Chen, Sheng, Li, Laiquan, Duan, Jingjing
• Format: Article
• Language: English
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202406605

To address the bottle-neck carbon-carbon coupling issue during electrochemical carbon dioxide reduction (eCO RR) to multicarbon (C ) products, this work develops an anion-directed strategy (Cl , NO , and SO ) to regulate interatomic distance of Cu diatoms. In comparison to pristine Cu (with a typical Cu-Cu distance of 2.53 Å), Cu-boroimidazole frameworks (BIF)/SO , NO , and Cl material shows elongated diatomic distance of 3.90 Å, 4.21 Å, and 3.30 Å, respectively. Among them, the Cu-BIF/Cl exhibits an outstanding eCO RR performance with a Faradaic efficiency of 72.12% for C products and an industrial-level current density of 539.0 mA cm at -1.75 V versus RHE. Significantly, according to theoretical and in situ experimental investigation, the highly electronegative Cl ion lifts d-band center of Cu sites of Cu-BIF/Cl, facilitating *CO adsorption with a low Gibbs free energy and its later dimerization overcoming a small energy barrier. In addition, this strategy to manipulate interatomic distance for diatomic catalysts, can also be adaptable to other reactions involving intermediate coupling and following the Langmuir-Hinshelwood mechanism, such as carbon-nitrogen coupling, nitrogen-nitrogen coupling, etc.