We report the study of two-dimensional graphitic carbon nitride (GCN) functionalized with copper single atoms as a catalyst for the reduction of CO₂ (CO2RR). The correct GCN structure, as well as the adsorption sites and the coordination of the Cu atoms, was carefully determined by combining experimental techniques, such as X-ray diffraction, transmission electron microscopy, X-ray absorption, and X-ray photoemission spectroscopy, with DFT theoretical calculations. The CO2RR products in KHCO₃ and phosphate buffer solutions were determined by rotating ring disk electrode measurements and confirmed by ¹H-NMR and gas chromatography. Formate was the only liquid product obtained in bicarbonate solution, whereas only hydrogen was obtained in phosphate solution. Finally, we demonstrated that GCN is a promising substrate able to stabilize metal atoms, since the characterization of the Cu-GCN system after the electrochemical work did not show the aggregation of the copper atoms.

我们报告了用铜单原子功能化的二维石墨氮化碳 (GCN) 作为还原 CO ₂ (CO2RR)的催化剂的研究。通过结合实验技术，如 X 射线衍射、透射电子显微镜、X 射线吸收和 X 射线光发射光谱，仔细确定了正确的 GCN 结构，以及吸附位点和 Cu 原子的配位， DFT 理论计算。KHCO ₃和磷酸盐缓冲溶液中的 CO2RR 产物通过旋转环盘电极测量确定，并通过¹H-NMR和气相色谱。甲酸盐是在碳酸氢盐溶液中获得的唯一液体产物，而在磷酸盐溶液中仅获得氢气。最后，我们证明了 GCN 是一种能够稳定金属原子的有前途的基材，因为电化学工作后 Cu-GCN 系统的表征没有显示出铜原子的聚集。