Metal-Organic Framework with High Densities of Open Metal Sites for Efficient Separation of Propylene from Propane

The separation of propylene/propane (C 3 H 6 /C 3 H 8 ) is a critical yet challenging process owing to their similar physical properties and molecular size. So it's urgent to explore efficient porous adsorbents to take place of the energy-intensive consumption and high cost of traditional cryogenic distillation technologies. Here, we report a mixed metal-organic framework (M'MOF), [Fe(pyz)Pt(CN) 4 ] (FePt-M'MOF, pyz=pyrazine) for selective adsorptive separation of C 3 H 6 /C 3 H 8 at room temperature, which has multiple functional sites and optimized pore channels of about 4.0 Å. This MOF has an excellent separation performance with C 3 H 6 uptake of 47.4 cm 3 /g and a high C 3 H 6 /C 3 H 8 selectivity of 4.7 under ambient conditions. The separation performance of propylene in this material is driven by π-π stacking and multiple intermolecular interactions between propylene molecules and the binding sites of FePt-M'MOF. This material can be prepared at room temperature and is stable in water, providing potential applications for industrial C 3 H 6 /C 3 H 8 separation.