Screening and Design of Covalent Organic Framework Membranes for CO2/CH4 Separation

Membrane based CO2/CH4 separation is an effective and energy saving way for highly demanded natural gas upgrading. Herein, high-throughput computational screening of covalent organic frameworks (COFs) for CO2/CH4 membrane separation is realized by using the 298 COF structures in CoRE COF database. Based on the study of structure-performance relationships, structural features of the outperformed COFs were identified and classified, followed by the structural design by decorating 11 CoRE COFs with 10 kinds of familiar functional groups. By evaluating the 290 designed COFs as membrane materials, the effectiveness and universality of -F and -Cl groups in improving the performance of various COFs were identified. The well-performed COFs were also computationally evaluated as fillers to make COF@polymer mixed matrix membranes, and improved separation performance was obtained.