Advanced Porous Materials in Mixed Matrix Membranes for CO₂ Capture

Membrane-based CO₂ separation has attracted extensive attention owing to its high energy efficiency, low operational cost, modular design, and continuous operation process. Among various membrane technologies, mixed matrix membranes (MMMs), which incorporate porous fillers into polymer matrices, have emerged as a promising strategy to overcome the permeability-selectivity trade-off and stability limitations of conventional polymeric membranes. This review comprehensively summarizes recent advances in advanced porous material-based MMMs for CO₂ capture, with particular emphasis on porous fillers including metal-organic frameworks, covalent organic frameworks, hydrogen-bonded organic frameworks, porous organic polymers, porous organic cages, and metal-organic cages. Various filler design strategies, such as functionalization, interfacial modification, hollow and core-shell structures, nanosheet architectures, in situ growth, and defect engineering, are systematically discussed for their effectiveness in improving interfacial compatibility and minimizing non-selective defects in MMMs. Furthermore, the separation performances of recently reported advanced porous material-based MMMs for CO₂/CH₄, CO₂/N₂, and H₂/CO₂ gas pairs are critically summarized and compared. Finally, the remaining challenges and future opportunities associated with membrane scalability, long-term stability, and industrial implementation are outlined to provide guidance for the development of next-generation MMMs for sustainable CO₂ capture.