Construction of F-containing porous organic framework with low CH₄ uptake and high C₃H₈/CH₄

Porous organic frameworks (POFs) represent a new family of porous materials distinguished by high chemical stability, thermal stability, structural tunabiltity, chemical functionality, and high porosity. In this study, we synthesized a F-containing POF, termed PAF-109 (PAF = porous aromatic framework), through the Schiff base reaction of 1,3,5-triformylphloroglucinol and 4,4′-Diaminoctafluorobiphenyl, with p-toluenesulfonic acid serving as the catalyst. Nitrogen sorption analysis revealed that PAF-109 shows a Brunauer − Emmet − Teller surface area of 718 m²/g, nearly four times greater than that of previously reported TpBD-F8. Interestingly, PAF-109 exhibits a low CH₄ uptake of only 0.18mmol/g at 298 K and 1 bar. Despite this, PAF-109 shows high selectivity for the separation of C ₃H₈ over CH₄.