Separation of methane and ethane using porous materials is a challenge. Size exclusion will reduce the working capacity and increase the difficulty of material fabrication. Covalent organic frameworks (COFs) are hopeful due to the adsorption selectivity of C₂H₆/CH₄ and other advantages. In this paper, we used the grand canonical Monte Carlo (GCMC) simulations to study the adsorption behavior of 1171 theoretical two-dimensional (2D) imine COFs, focusing on the effects of monomer structure and composition on the and C₂H₆/CH₄ separation performance. 11 structures with excellent performance were screened according to C₂H₆ working capacity and the C₂H₆/CH₄ selectivity. COFs with trigonal nodes were found to have better performance than that with tetragonal nodes. It is supposed that the shape, size, and spatial ductility of the nodes have important effects on structural parameters such as largest free sphere diameter (LCD), surface area, and void fraction. In addition, the nitrogen content of these COFs also has a significant effect on the separation performance of CH₄ and C₂H₆, which is mainly related to the way of nitrogen introduction. We hope that the results of this study can provide guidance for the monomer selection and structural design of the separation materials for CH₄ and C₂H₆.

使用多孔材料分离甲烷和乙烷是一项挑战。尺寸排阻会降低工作能力并增加材料制造的难度。由于C ₂ H ₆ /CH ₄的吸附选择性和其他优点，共价有机骨架（COF）很有希望。在本文中，我们使用大正则蒙特卡罗 (GCMC) 模拟研究了 1171 种理论二维 (2D) 亚胺 COF 的吸附行为，重点研究了单体结构和组成对 C ₂ H ₆ /CH和 C ₂ H ₆ /CH 的影响。₄分离性能。根据C ₂ H ₆筛选出11种性能优良的结构工作容量和C ₂ H ₆ /CH ₄选择性。发现具有三角形节点的 COF 比具有四边形节点的 COF 具有更好的性能。据推测，节点的形状、尺寸和空间延展性对最大自由球直径 ( LCD )、表面积和空隙率等结构参数有重要影响。此外，这些COFs的氮含量对CH ₄和C ₂ H ₆的分离性能也有显着影响。，这主要与氮的引入方式有关。希望本研究结果能为CH ₄和C ₂ H ₆分离材料的单体选择和结构设计提供指导。