Interfacial polymerization-engineered MOF membranes with tailored CO2 nanochannels for robust gas separation

Mixed matrix membranes (MMMs) incorporating metal-organic frameworks (MOFs) hold great promise for energy-efficient carbon capture, yet are fundamentally limited by interfacial defects and the ubiquitous permeability-selectivity trade-off. Herein, we propose a nanoconfinement strategy via in-situ interfacial polymerization to synthesize ultrathin MOF nanosheets and thus integrate them into PIM-1 matrix, a typical representative of polymers of intrinsic microporosity (PIMs), crafting a defect-free membrane. The meticulously designed MOFs, featuring synergistic amino functionalities and unsaturated Cu 2+ sites, endows the optimal membrane (PIM-MOF-1%) with exceptional CO 2 affinity and tailored molecular-sieving pathways. Consequently, it achieves a remarkable combination of high CO 2 permeability (5186 barrer) and CO 2 /N 2 selectivity (41), surpassing the 2019 Robeson upper bound. Impressively, this superiority persists under harsh conditions-exceeding the 2008 Robeson upper bound at 80 °C and sustaining high performance at 15 bar. Moreover, the membrane demonstrates exceptional long-term durability, preserving excellent separation performance, with CO 2 permeability of 3078 barrer and CO 2 /N 2 selectivity of 46, even after 180 days of aging. Our strategy aligns nanoconfined MOF architectures with polymer matrix, thereby resolving critical challenges in carbon capture through the simultaneous enhancement of separation efficiency and durability.