Highly Robust Zr-MOF Platform Featuring Aromatic-Rich Cores for Efficient Paraffin/Olefin Separation

Paraffin–olefin separations are essential for polymer-grade feedstock production but remain highly energy-intensive via cryogenic distillation, given the similar boiling points and molecular sizes of these hydrocarbons. Metal–organic frameworks (MOFs) provide a promising alternative owing to their high surface areas, tunable porosities, and vast array of functional groups. There is growing interest in reverse-selective MOFs, which favor paraffins via C–H···π interactions between sp3-hybridized C–H bonds and aromatic regions within the framework. These materials reduce the separation burden on the unadsorbed phase, delivering olefin-enriched streams under comparatively mild conditions. Here, we introduce a zirconium-based MOF (Zr-pbpta) featuring aromatic-rich cores and pyridyl functionalities that achieves notable ethane and propane uptake capacities of 4.55 and 8.50 mmol g–1 (1 bar, 298 K), surpassing many benchmark MOFs. It also demonstrates high C2H6/C2H4 and C3H8/C3H6 selectivity, driven by strong alkane–framework interactions confirmed via in situ IR measurements. The presence of aromatic moieties and a high density of pyridyl nitrogen sites enabled the high uptake and selectivity observed for the MOF.