Ab initio screening of CO₂-philic groups

Ab initio calculations were used to identify CO₂-philic groups. Over 55 neutral molecules were screened for CO₂ affinity via binding energetics. It is found that poly(ethylene oxide)s (PEO) oligomers with more than three repeating units are good CO₂-binding groups, consistent with the high-performance of PEO-based materials for CO₂/N₂ separation. More interestingly, two triazole groups linked with a methylene chain are also excellent for CO₂ binding with a favorable interaction of more than 28 kJ/mol, indicating that polymers or covalent-organic frameworks (COFs) with triazoles may be utilized for CO₂ capture. This work provides a useful guide to introduce promising organic groups into polymeric membranes and COFs for CO₂/N₂ separation media.