Thermodynamic and Kinetic Separation Within a Flexible Hydrogen Bonded Organic Framework for Ternary Benzene/Cyclohexene/Cyclohexane Mixture

The separation of benzene (Bz), cyclohexene (CHE), and cyclohexane (CHA) is crucial in the petrochemical industry but remains highly challenging due to their similar boiling points and molecular kinetic sizes. Herein, we report HOF-FJU-112a, a flexible HOF material constructed from self-assembled π-pillars with suitable and adaptive one-dimensional channels (3.6 × 6.0 Å), for thermodynamic and kinetic separation of Bz, CHE, and CHA ternary mixture. Specifically, HOF-FJU-112a is capable of thermodynamically separating Bz/CHA and CHE/CHA, while kinetically separating Bz/CHE, simultaneously leading to a complete separation of the Bz/CHE/CHA ternary mixture. Breakthrough and elution experiments confirm efficient binary and ternary separation, including complete resolution of Bz/CHE/CHA mixtures into three pure components (99.9%) in one single column, with the outstanding breakthrough yield. This study demonstrates a new design paradigm for multifunctional HOFs and affirms their promise in challenging C6 hydrocarbon separations.