A Highly Stable Anion-Functionalized Cage-like Framework for Efficient Separation of MTO Products under Harsh Conditions

Separation of methanol-to-olefin products to obtain high-purity C 2 H 4 and C 3 H 6 has been deemed as one sustainable method for providing such indispensable industrial feedstocks. To meet the practical separation conditions, it is of critical significance to develop adsorbents that can separate C 3 H 6 /C 2 H 4 under high-temperature and high-humidity conditions. Herein, we reported an anion-functionalized cage-like MOF (SIFSIX-Cu-TPA) showing a high-stability structure and huge distinction in C 3 H 6 and C 2 H 4 adsorption. Furthermore, C 3 H 6 - and C 2 H 4 -loaded single-crystal structures clearly reveal that more supramolecular interactions are generated between the C 3 H 6 molecule and SIFSIX-Cu-TPA. Breakthrough experiments show that SIFSIX-Cu-TPA can efficiently separate C 3 H 6 /C 2 H 4 . After one separation cycle, 3.5 mol kg –1 of high-purity C 2 H 4 (>99.95%) and 2.5 mol kg –1 of polymer-grade C 3 H 6 (>99.5%) can be obtained from a C 3 H 6 /C 2 H 4 (50/50) mixture at 2 98 K. More importantly, even at 338 K and 100% relative humidity, polymer-grade C 2 H 4 (2.7 mol kg –1 ) and C 3 H 6 (1.4 mol kg –1 ) can also be collected.