A Microporous Hydrogen‐Bonded Framework With Anthracenyl Motifs for Efficient Reversed Ethylene/Ethane Separation

ABSTRACT Direct acquisition of polymer‐grade ethylene from ethane/ethylene (C 2 H 6 /C 2 H 4 ) mixtures remains a formidable industrial challenge. While hydrogen‐bonded organic frameworks (HOFs) offer a promising low‐energy platform, their inherent structural flexibility often compromises stability and separation performance. Herein, we introduce a dual‐purpose “Z‐pinning” strategy to construct a robust HOF, HOF‐FJU‐202, for highly efficient reversed C 2 H 4 /C 2 H 6 separation. Anthracenyl motifs serve as molecular “Z‐pins” oriented perpendicular to hydrogen‐bonded layers, bridging them via edge‐to‐face π ‐interactions. This significantly enhances out‐of‐plane stability and chemical/thermal robustness. Simultaneously, these channel‐lining anthracenyl groups act as π ‐rich sites preferentially binding C 2 H 6 via multiple C─H··· π interactions. This synergistic architecture delivers polymer‐grade C 2 H 4 with a productivity of 11.2 L/kg from equimolar mixtures and a record 25.5 L/kg from 10/90 lean mixtures, setting a new benchmark for HOF materials. Furthermore, HOF‐FJU‐202 is readily synthesized on a 20 g scale and processed into robust granules with a compressive strength of 32.1 N, while showing negligible performance loss, underscoring its practical potential. Comprehensive crystallographic, spectroscopic, and computational analyses confirm that the anthracenyl Z‐pins are critical for both maintaining structural integrity and facilitating preferential C 2 H 6 capture. These findings demonstrate that integrating mechanical reinforcement with functional recognition sites is a potent strategy for developing stable, task‐specific porous materials.