Metal–Organic Framework-Based Single-Molecule SF6 Trap for Record SF6 Capture

Pursuing best-performing porous adsorbents to realize an effective SF6 recovery from SF6/N2 blends is of pronounced industrial worth. To tackle this key obstacle, we propose a single-molecule SF6 trap, which is based upon a splint-like pore in a highly stable metal–organic framework Ni(adc)(dabco)0.5 through multipoint F···π affinity. The pore walls are decorated with oppositely parallel anthracene rings, and the overlapping region of anthracene rings forms a giant overlap of potential fields. This very strong SF6 trap presents a record initial isosteric heat of adsorption (47.6 kJ mol–1), Henry constant (285.0 mmol g–1 bar–1), and uptake (2.23 mmol g–1) for SF6, making it a new benchmark with an unexampled ideal selectivity (919.4) toward SF6 capture. The SF6 adsorption mechanism within the Ni(adc)(dabco)0.5-based single-molecule trap is identified via in situ powder X-ray diffraction and Fourier transform infrared reflection spectroscopy in conjunction with theoretical studies. The highest selectivity (948.2), SF6 breakthrough uptake (2.1 mmol g–1), and dimensionless time (481.6) with the breakthrough effect of complete separation further consolidated that this MOF-based single-molecule SF6 trap is a novel state-of-the-art candidate toward SF6/N2 separation.