Zinc Pyrazolate Framework with Knotted‐Like Chains for Separation of Propylene/Ethylene Mixtures

Abstract Ethylene and propylene are important raw chemicals that are in high demand. Methanol‐to‐olefins (MTO) is a promising alternative approach for producing ethylene from non‐petroleum feedstocks, in which the separation of propylene/ethylene is particularly crucial. In this study, a metal azolate framework (MAF) [Zn 7 ( μ ‐H 2 O)(tppa) 4 (HCOO) 2 ] (MAF‐68, where H 3 tppa = tris(4‐(1‐(tetrahydro‐2 H ‐pyran‐2‐yl)‐1 H ‐pyrazol‐4‐yl)phenyl)amine) has been synthesized with rare zinc pyrazolate chains comprising μ ‐H 2 O bridges, namely Zn 7 ( μ ‐H 2 O)(Rpz) 12 (HCOO) 2 (Rpz − denotes pyrazolate groups), for the separation of propylene/ethylene mixtures. Sorption experiments indicated that MAF‐68 shows a remarkable uptake of 4.19 mmol g −1 for propylene (at 10 kPa), which is significantly higher than those of many other reported porous materials for C 3 H 6 /C 2 H 4 separation. MAF‐68 also shows a high selectivity of 9.5 for 2/5 C 3 H 6 /C 2 H 4 . Breakthrough experiments further confirm the separation potential of this material for high‐purity C 3 H 6 (99.9999%) and C 2 H 4 (99.9999%).