Synergistic C<sub>2</sub>H<sub>2</sub> Binding Sites in Hydrogen‐Bonded Supramolecular Framework for One‐Step C<sub>2</sub>H<sub>4</sub> Purification from Ternary C2 Mixture
Zhenyu Ji, Qing Li, Yunzhe Zhou, Rajamani Krishna, Maochun Hong, Mingyan Wu
Abstract
Abstract Purification of C 2 H 4 from the ternary C2 hydrocarbon mixture in one step is of critical significance but still extremely challenging according to its intermediate physical properties between C 2 H 6 and C 2 H 2 . Hydrogen‐bonded organic frameworks (HOFs) stabilized by supramolecular interactions are emerging as a new kind of adsorbents that facilitate green separation. However, it remains a problem to efficiently realize the one‐step C 2 H 4 purification from C 2 H 6 /C 2 H 4 /C 2 H 2 mixture because of the low C 2 H 2 /C 2 H 4 selectivity. We herein report a robust microporous HOF (termed as HOF‐TDCPB) with dense O atoms and aromatic rings distributed on the pore surface which provide C 2 H 6 and C 2 H 2 preferred environment simultaneously. Dynamic breakthrough experiments indicate that HOF‐TDCPB can not only obtain high‐purity C 2 H 4 from binary C2 mixture, but also firstly realize one‐step C 2 H 4 purification from ternary C 2 H 6 /C 2 H 4 /C 2 H 2 mixture, with the C 2 H 4 productivity of 3.2 L/kg (>99.999 %) for one breakthrough cycle. Furthermore, HOF‐TDCPB displays outstanding stability in air, organic solvents and water, which endow it excellent cycle performance even under high‐humidity conditions. Theoretical calculations indicate that multiple O sites on pore channels can create synergistic binding sites for C 2 H 2 , thus affording overall stronger multipoint interactions.