Control over Electrochemical CO(2) Reduction Selectivity by Coordination Engineering of Tin Single‐Atom Catalysts

Carbon‐based single‐atom catalysts (SACs) with well‐defined and homogeneously dispersed metal−N(4) moieties provide a great opportunity for CO(2) 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 SnN(3)O(1) active sites supported on N‐rich carbon matrix (Sn‐NOC) for efficient electrochemical CO(2) reduction. Contrary to the classic Sn‐N(4) configuration which gives HCOOH and H(2) as the predominant products, Sn‐NOC with asymmetric atomic interface of SnN(3)O(1) gives CO as the exclusive product. Experimental results and density functional theory calculations show that the atomic arrangement of SnN(3)O(1) reduces the activation energy for *COO and *COOH formation, while increasing energy barrier for HCOO* formation significantly, thereby facilitating CO(2)‐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.