Aromaticity Regulation in Isostructural Metal‐Organic Frameworks for Propyne Storage and Propylene Purification

We report the exceptional propyne (C 3 H 4 ) storage and propylene (C 3 H 6 ) purification in a metal‐organic framework, PKU‐101, controlled via regulation of aromaticity. The pyrene‐fused pore interior of PKU‐101 provides multiple C─H···π interactions for alkyne, resulting in a record C 3 H 4 adsorption of 250 cm 3 cm −3 at 298 K and 1 bar, representing a benchmark sorbent for C 3 H 4 . Additionally, the supramolecular interactions enable fine thermodynamic discrimination for alkenes, resulting in excellent separation of C 2 H 4 /C 3 H 6 ( v / v = 1/1), delivering simultaneously high productivities of C 3 H 6 and C 2 H 4 (267 and 174 L kg −1 , respectively; C 2 H 4 purity > 99.9 %). Effective separation of C 3 H 6 /C 3 H 8 ( v / v = 1/1) and C 3 H 4 /C 3 H 6 ( v / v = 1/99) with a high C 3 H 6 productivity of 532 L kg −1 (purity of 99.99 %) has also been achieved by PKU‐101. In situ crystallographic and spectroscopic studies confirmed the key role of enhanced aromaticity on the discrimination of alkanes/alkenes/alkynes. Importantly, these weak supramolecular interactions enable complete regeneration at only 318 K.