Guanosine-derived atomically dispersed Cu-N3-C sites for efficient electroreduction of carbon dioxide
Shuo Chen, Miao Xia, Xuefei Zhang, Lisun Pei, Zijia Li, Xin Ge, Mei‐Jin Lin, Wei Zhang, Zailai Xie
Abstract
Single-atom copper (Cu) embedded within carbon catalysts have demonstrated significant potential in the electrochemical reduction of carbon dioxide (CO 2 ) into valuable chemicals and fuels. Herein, we develop a straightforward and template-free strategy for synthesizing atomically dispersed Cu N C catalysts (CuG) by annealing the self-assembled guanosine. The CuG catalysts display two-dimensional morphology, tunable pore size and large surface areas that can be adjusted by changing carbonization temperature. Spherical aberration-corrected transmission electron microscopy reveals that single-atom Cu are homogeneously dispersed on the surface of carbon nanosheets. The optimum CuG-1000 catalysts achieve a high CO Faradaic efficiency (FE co ) up to 99% and a high CO current density of 6.53 mA cm −2 (−0.65 V vs. RHE). Besides, the flow cell test of CuG-1000 shows a high current density up to 25.2 mA cm −2 and the FE co still exceeded 91% after more than 20 h of testing. Specifically, the existence of Cu-N 3 -C active sites was proved by extended X-ray absorption fine structure (EXAFS). Density functional theory evidences that tricoordinated copper with N can largely regulate the adsorption and desorption of key intermediates by transferring electrons to *COOH through Cu atoms, thereby improving selectivity toward CO. This work demonstrates the active origin of Cu N C catalysts in CO 2 electroreduction and offers a blueprint to construct atomically dispersed transition site catalysts by supramolecular self-assembly strategy.