Basic Alkylamine Functionalized PAF‐1 Hybrid Membrane with High Compatibility for Superior CO2 Separation from Flue Gas

Abstract Functionalized porous aromatic frameworks (PAFs) are excellent candidate materials for hybrid membrane fabrication. However, tailoring PAFs for membrane CO 2 separation with desirable performance is still a challenge. Here, facile fabrication of functional hybrid alkylamine‐modified PAF‐1 containing membranes with high compatibility for efficient CO 2 /N 2 separation is reported. The methylamino groups are installed on PAF‐1 resulting in PAF‐1‐CH 2 NH 2 that has a high surface area of over 1400 m 2 g –1 and unique CO 2 adsorption with CO 2 /N 2 thermodynamic selectivity of over 1000. Amidation reaction is developed for PAF‐1‐CH 2 NH 2 cross linking with cPIM‐1 (carboxylic polymer of intrinsic microporosity), giving a homogenous compatible membrane of PAF‐1‐CH 2 NH 2 —cPIM‐1 with outstanding CO 2 permeability (≈10790 Barrer) and high CO 2 /N 2 permselectivity (≈43). This membrane outperforms the counterparts derived from parent PAF‐1 and phenylamine PAF‐1 and possesses superior performance to other relevant membranes for CO 2 /N 2 separation. Such a membrane can selectively and stably separate CO 2 from N 2 in a simulated flue gas mixture, demonstrating its huge potential in carbon capture.