Direct acquisition of polymer-grade ethylene from ethane/ethylene (C2H6/C2H4) 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 C2H4/C2H6 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 C2H6 via multiple C─H···π interactions. This synergistic architecture delivers polymer-grade C2H4 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 C2H6 capture. These findings demonstrate that integrating mechanical reinforcement with functional recognition sites is a potent strategy for developing stable, task-specific porous materials.
Xu et al. (2026) studied this question.