Co-fa nanoplates incorporated 6FDA-DAM mixed-matrix membranes for enhanced CO₂/CH₄ separation

Plate-like or sheet-like porous materials with nanometer thickness have been considered as the preferred fillers to improve mixed-matrix membranes (MMMs)-based separation. Herein, hexagonal Co-fa (HG-Co-fa) nanoplates were simply synthesized without the addition of any modifier and used as fillers to construct 6FDA-DAM-based MMMs for efficient CO₂/CH₄ separation. HG-Co-fa nanoplates exhibit high dispersion and interface compatibility in 6FDA-DAM matrix. The results demonstrated that the CO₂/CH₄ separation performance of 6FDA-DAM was obviously improved after the incorporation of HG-Co-fa nanoplates. The resultant MMMs with nanoplate loading of 10 wt% showed CO₂/CH₄ selectivity of 27 and CO₂ permeability of 1419 Barrer at 25 ℃ and 0.2 MPa, surpassing 2008 Robeson upper bound. Meanwhile, the high lattice integrity and structural stability of HG-Co-fa nanoplates contribute to the excellent thermal and mechanical stability of MMMs, contributing to their anti-plasticization property up to 14 bar and long-term stability up to 240 h, indicating their potential for natural gas separation.