Control over Electrochemical CO2 Reduction Selectivity by Coordination Engineering of Tin Single‐Atom Catalysts

• Published in: Advanced science 2021-12, Vol.8 (23), p.e2102884-n/a
• Main Authors: Guo, Jiangyi, Zhang, Wenlin, Zhang, Lu‐Hua, Chen, Datong, Zhan, Jiayu, Wang, Xueli, Shiju, N. Raveendran, Yu, Fengshou
• Format: Article
• Language: English
• Subjects: Adsorption; asymmetric SnN3O1 configuration; Carbon; CO selectivity; CO2 reduction reaction; electrochemistry; Oxidation; single‐atom catalysts; Wavelet transforms
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202102884

Carbon‐based single‐atom catalysts (SACs) with well‐defined and homogeneously dispersed metal−N4 moieties provide a great opportunity for CO2 reduction. However, controlling the binding strength of various reactive intermediates on catalyst surface is necessary to enhance the selectivity to a desired product, and it is still a challenge. In this work, the authors prepared Sn SACs consisting of atomically dispersed SnN3O1 active sites supported on N‐rich carbon matrix (Sn‐NOC) for efficient electrochemical CO2 reduction. Contrary to the classic Sn‐N4 configuration which gives HCOOH and H2 as the predominant products, Sn‐NOC with asymmetric atomic interface of SnN3O1 gives CO as the exclusive product. Experimental results and density functional theory calculations show that the atomic arrangement of SnN3O1 reduces the activation energy for *COO and *COOH formation, while increasing energy barrier for HCOO* formation significantly, thereby facilitating CO2‐to‐CO conversion and suppressing HCOOH production. This work provides a new way for enhancing the selectivity to a specific product by controlling individually the binding strength of each reactive intermediate on catalyst surface. A Sn‐based single‐atom catalyst with asymmetric atomic interface of SnN3O1 is designed and synthesized to switch the product of CO2 reduction from HCOOH to CO with an impressive FECO of 94%.