Layered MOF membranes modified with ionic liquid/AgBF4 composite for olefin/paraffin separation

Olefin/paraffin separation is one of the most important chemical process in petrochemical industry. Relative to currently used cryogenic distillation with high energy penalty, membrane-based separation has the potential to significantly reduce energy consumption. MOF membranes have emerged as a promising candidate for gas separation owing to its uniform porous structures and diversified chemical components. However, the scarcity of reliable synthesis methods limits the application of MOF membranes for olefin/paraffin separation. Here, we propose the layered MOF membranes modified with ionic liquid/AgBF 4 composite for olefin/paraffin separation, which exhibit impressive separation performances for mixed gases (C 3 H 6 permeance: 129.8 ± 40.4 GPU; C 3 H 6 /C 3 H 8 separation factor: 28.8 ± 3.8; C 2 H 4 permeance: 45.6 ± 23.7 GPU; C 2 H 4 /C 2 H 6 separation factor: 12.0 ± 2.2). This work, avoiding a complicated de novo design of microstructure of membrane, demonstrates a facile but effective strategy to convert an “inert” membrane to olefin-selective one. • Layered MOF membranes were modified with the composite Ag + /ionic liquid. • Post-modification converted inert membranes to olefin-selective candidates. • Both excellent separations of C 3 H 6 /C 3 H 8 and C 2 H 4 /C 2 H 6 were realized.