High-performance carbon molecular sieve membrane derived from PEK-N polymer for CO₂ separation

Carbon molecular sieve (CMS) membranes demonstrate promising economic and environmental advantages in gas separation applications. In this work, we synthesized a novel polymer precursor of PEK-N and utilized it to fabricate a series of PEK-N derived CMS membranes. With varying carbonization temperature and time, the pore structures and gas separation performance were finely tuned. The gas separation properties of membranes with different carbonization temperature were comprehensively evaluated. In particular, by carbonizing the sample at 650 °C for 1 h, PEK-N derived CMS membranes (CMS-650-1) achieved the highest CO₂ permeability around 2176 Barrer, and selectivities of 48.2 for CO₂/N₂ and 57.8 for CO₂/CH₄ in their gas mixtures. Our study suggests that the use of rationally designed polymers has the potential to bring about high gas separation performance for polymer-derived carbon molecular sieve membranes.