Thermally Modified γ‐CD‐MOF Monoliths for Durable and Efficient One‐Step CO ₂ Purification From Hydrocarbons

ABSTRACT The removal of carbon dioxide (CO 2 ) impurities from hydrocarbons is vital for natural gas purification and other industrial processes. Conventional powdered MOFs, however, often suffer from handling difficulties and limited stability under humid conditions, restricting their practical deployment. In this work, we demonstrate thermally modified cyclodextrin MOF (CD‐MOF) monoliths as robust adsorbents for CO 2 separation. Thermal treatment generates a thin amorphous carbon coating, which protects the framework against hydrolysis while maintaining crystallinity and adsorption performance after 30 days of exposure to 90% relative humidity. The monolithic CD‐MOF exhibits a CO 2 uptake of 60.0 cm 3 g −1 at 298 K and 100 kPa, outperforming most state‐of‐the‐art adsorbents. Ideal adsorbed solution theory (IAST) predicts an outstanding CO 2 /CH 4 (1:99) selectivity of ∼2500. Breakthrough experiments with single‐component and multicomponent mixtures (CO 2 /CH 4 /C 2 H 2 /C 2 H 4 /C 2 H 6 ) further confirm efficient CO 2 capture even under high humidity. These findings highlight the advantages of shaping MOFs into water‐stabilized monoliths, offering a practical pathway toward durable and high‐performance CO 2 removal in hydrocarbon purification.