Construction of an Al‐Based MOF with Methyl‐Functionalized Microporous Nano‐Traps for Efficient Separation of SF ₆ /N ₂

ABSTRACT Sulfur hexafluoride (SF ₆ ) is indispensable to the power industry, yet its emission requires strict control due to the potent greenhouse effect. The direct recovery of high‐purity SF ₆ from industrial waste gas is vital for sustainable use but remains a formidable challenge. Herein, we report NU‐62, an Al‐MOF featuring methyl‐functionalized microporous nano‐traps, engineered by employing a hexacarboxylate ligand with three methyl groups on its backbone and two types of unusual 4‐connected trinuclear Al clusters coordinated with formates and acetates. Leveraging the tailored pore environments, NU‐62 exhibited a high SF ₆ uptake of 3.99 mmol g ⁻¹ and an outstanding SF ₆ /N ₂ (10:90, v/v) selectivity of 209 at 298 K and 1 bar, achieving highly selective SF ₆ capture from SF ₆ /N ₂ mixture. Furthermore, breakthrough experiments confirm its efficient separation for an SF ₆ /N ₂ mixture, with good performance retained even under 70% relative humidity. Theoretical calculations suggest that SF ₆ is preferentially adsorbed in the methyl‐functionalized nano‐traps through multiple C─H···F hydrogen bonding interactions. This work demonstrates the great potential of methyl‐functionalized pore engineering in enabling energy‐efficient and sustainable SF ₆ recovery for industrial applications.