Basic Alkylamine Functionalized PAF‐1 Hybrid Membrane with High Compatibility for Superior CO 2 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.