A new yttrium‐based metal–organic framework for molecular sieving of propane from propylene with high propylene capacity

Abstract Developing energy‐efficient alternatives for propylene (C3H6) and propane (C3H8) separation is of great significance and challenge in the petrochemical industry. Herein, we report the rational design of a new yttrium‐based ultramicroporous metal–organic framework (MOF) comprised of 12‐connected hexanuclear [Y6(OH)8(COO)12]2− cluster and 5‐(3,5‐dicarboxybenzoylamino)isophthalic acid (H4dbai) with ftw topology. It possesses a suitable pore window size and a relatively large pore volume for molecular sieving separation of C3H8 from C3H6 with a high C3H6 capacity. At 298 K and 100 kPa, the adsorption capacity of C3H6 was 2.57 mmol/g, which is the highest among the reported C3H6/C3H8 molecular sieving MOF adsorbents. The molecular simulation revealed that the steric hindrance effect together with the electrostatic interaction of the oxygen sites in the window resulted in the molecular sieving separation of C3H6/C3H8. The breakthrough experiments confirmed its excellent separation performance under dynamic conditions to produce high purity (97.1%) of C3H6 with a working adsorption capacity of 1.75 mmol/g.