Synergistic Binding Sites in a Robust and Scalable Metal-Organic Framework for Record CH₄ Capture

Effectual CH₄ reclamation from CH₄/N₂ blends by existing physisorbents in industrialization confronts the adversity of frustrated separation performance, weak structural strength, and restricted scale-up preparation. To solve aforesaid bottlenecks, herein, a strategy is presented to fabricate synergistic strong recognition binding sites in a robust and scalable optimum Cu(pma)₂ with ultramicroporous feature regarding superb CH₄ separation versus N₂. By virtue of the synergistic contribution of multiple affinities accompanied by enormous potential field overlap of pore restriction, it imparts strong recognition binding toward CH₄ molecules. Equilibrium adsorption bears a record KH, CH₄ (88.2 cm³(STP) g^-1 bar^-1), CH₄ uptake (48.5 cm³(STP) g^-1 bar^-1), CH₄ stacking density (303.9 g L^-1), separation potential (1.52 mol L^-1) coexisting with one of the highest CH₄/N₂ selectivity (11.5) and Q0 st, CH₄ (29.8 kJ mol^-1) hitherto, authorizing a novel benchmark. Thermodynamically driven separation mechanisms within Cu(pma)₂-established synergy of strong recognition forces are deciphered by in situ PXRD and FT-IR combined with theoretical studies. The breakthrough effect of the highest CH₄ dynamic uptake (28.8 cm³(STP) g^-1) in cooperation with exceptional recyclability and easy synthesis scalability under ambient conditions strengthened the attractiveness of Cu(pma)₂.