High‐Density Edge‐Hosted Ni Single Atoms on Nanoscale Carbon for Boosting Electrocatalytic CO₂ Reduction

Edge‐hosted single‐atom sites provide asymmetric charge distribution compared with in‐plane sites, showing higher intrinsic activity. However, traditional preparation methods for edge sites rely on creating mesopores by etching, making it difficult to obtain high‐density edge sites. Herein, it is demonstrated that reducing the size of carbon support to the nanoscale by a nanocasting approach enables high‐density edge‐hosted single‐atom sites, significantly enhancing the catalytic performance in electrochemical CO 2 reduction. To achieve this, edge Ni sites on N‐doped carbon (e‐Ni/NC) with an average size of 26 nm are prepared by calcination of ZIF‐L confined within SBA‐16. e‐Ni/NC achieves a CO current density of 480.4 mA cm −2 and a CO Faradaic efficiency over 90.0% from −0.6 to −1.6 V, which are superior to the in‐plane Ni sites on N‐doped carbon. The Zn–CO 2 battery with e‐Ni/NC cathode possesses a maximum power density of 1.2 mW cm −2 and shows stable performance in galvanostatic charge–discharge cycling.