Reticular Chemistry-Guided Topology Engineering of Pillar-Layer Metal-Organic Frameworks for Boosting SF₆/N₂...

Pillar-layered metal-organic frameworks (MOFs) hold high promise in the field of gas adsorption and separation. Capitalizing on reticular chemistry and topology-guided pore engineering, we herein present a rare non-interpenetrated MOF based on the pillaring of hxl layer, comprised of hexanuclear Ni₆ clusters bridged by mixed O- and N-donor linkers. Notably, it features uniform triangular channels with optimal ultramicropore size and positive surface potential, constituting a molecular trap for SF₆. By leveraging such pore characteristics, a commendable low-pressure adsorption capacity and selectivity for SF₆ over N₂ is achieved, significantly superior to the counterparts of pillared sql- and kgm-MOFs and on par with some leading adsorbents. A joint theoretical and crystallographic study reveals the superiority of topology-directed pore regulation on SF₆ adsorption. Breakthrough experiments demonstrate that this MOF is capable of recovering high-purity (>99.9%) SF₆ from binary SF₆/N₂ mixture (10/90, v/v) at ambient conditions, attaining a record-high productivity in a single adsorption-desorption cycle. Moreover, excellent stability and scalable synthesis with low costs confer it with a great application prospect.