(371f) Metal–Organic Framework-Loaded Nanofibrous Aerogels As 3D Matrices for CO? Capture

This study investigates the synthesis and performance of mesoporous UiO-66-NH₂ Metal-Organic Framework (MOF)-impregnated CDA (cellulose diacetate)-silica hybrid nanofibrous aerogels (NFAs) for efficient CO₂ capture. Mesoporous MOFs generally surpass microporous ones in CO₂ adsorption, while NFAs provide a lightweight, highly porous platform with a 3D nanofiber network, ensuring mechanical stability and enhanced surface area. By leveraging these advantages, we fabricate CDA-silica@UiO-66-NH₂ NFAs via a straightforward freeze-drying process, combining CDA-silica nanofiber dispersions with mesoporous UiO-66-NH₂ nanoparticles in tert-butanol. This approach eliminates the need for complex pre- or post-processing steps typically associated with aerogel synthesis. The resulting aerogels feature a hierarchical porous architecture, support high MOF loadings (up to 80 wt.%), and exhibit exceptional CO₂ adsorption capacity, with adsorption directly correlating to MOF content. Notably, an 80 wt.% MOF-loaded NFA captures 2.5 mmol/g of CO₂ at 35°C under atmospheric pressure. The material also demonstrates strong CO₂ selectivity over N₂ across all pressures when tested with an 85:15 CO₂/N₂ gas mixture, achieving an IAST-calculated CO₂/N₂ selectivity of 18.2 at 298 K. Additionally, the NFA maintains structural resilience, including compressibility and fatigue resistance, while ensuring stable MOF integration without detachment during repeated compression cycles. Unlike conventional CO₂ sorbents, our CDA-silica@UiO-66-NH₂ NFA combines high CO₂ selectivity, adsorption capacity, durability, and scalable fabrication, making it a promising candidate for real-world carbon capture applications.