Covalent organic frameworks (COFs) with amine linkage in both three and two dimensions, COF-300-AR and COF-366-M-AR, were synthesized by direct reduction of their corresponding COFs with imine linkage, COF-300 and COF-366-M, respectively. The quantitative reduction was confirmed by Fourier transform infrared and cross-polarization magic angle spinning NMR (both ¹³C and ¹⁵N) spectroscopy. These amine COFs were highly crystalline and exhibited excellent chemical stability in strong acids and bases. The abundant amino groups in the COF-300-AR backbone facilitated the electrochemical reduction of CO₂ on silver electrodes in a concerted manner and led to selective generation of CO. Specifically, CO conversion efficiency was raised from 13% to 53% at −0.70 V and from 43% to 80% at −0.85 V (versus a reversible hydrogen electrode) in comparison with that of a bare silver electrode. The porosity of COFs favored molecular diffusion to the electrode surface, and the amine functional groups close to the electrode surface promoted CO₂ conversion efficiency by forming carbamate intermediates.

通过直接还原具有亚胺键的相应COF，COF-300和COF-366，在三个维度和两个维度上具有胺键的共价有机骨架（COF）合成了COF-300-AR和COF-366-M-AR -M，分别。通过傅立叶变换红外和交叉极化魔角旋转NMR（¹³ C和¹⁵ N）光谱确认了定量还原。这些胺的COF具有很高的结晶度，并且在强酸和强碱中表现出出色的化学稳定性。COF-300-AR主链中丰富的氨基基团促进了CO ₂的电化学还原在银电极上协同作用并导致选择性产生CO。具体而言，在-0.70 V时，CO转化效率从13％提高到53％，在-0.85 V时从43％提高到80％（相对于可逆氢电极）与裸银电极相比。COF的孔隙率有利于分子扩散到电极表面，并且靠近电极表面的胺官能团通过形成氨基甲酸酯中间体提高了CO ₂转化效率。