A novel hydrophobic carborane-hybrid microporous material for reversed C 2 H 6 adsorption and efficient C 2 H 4 /C 2 H 6 separation under humid conditions.

Since ethylene (C 2 H 4 ) is important feedstock in the chemical industry, developing economical and energy-efficient adsorption separation techniques based on ethane (C 2 H 6 )-selective adsorbents to replace the energy-intensive cryogenic distillation is highly demanded, which however remains a daunting challenge. While previous anionic boron cluster hybrid microporous materials display C 2 H 4 -selective features, we herein reported that the incorporation of a neutral para -carborane backbone and aliphatic 1,4-diazabicyclo[2.2.2]octane (DABCO) enables the reversed adsorption of C 2 H 6 over C 2 H 4 . The generated carborane-hybrid microporous material ZNU-10 (ZNU = Zhejiang Normal University) is highly stable in humid air and maintains good C 2 H 6 /C 2 H 4 separation performance under high humidity. Gas loaded single crystal structure and density-functional theory (DFT) calculations revealed that the weakly polarized carborane and DABCO within ZNU-10 induce more specific C-H δ + ⋯H δ - -B dihydrogen bonds and other van der Waals interactions with C 2 H 6 , while the suitable pore space allows the high C 2 H 6 uptake. Approximately 14.5 L kg -1 of polymer grade C 2 H 4 can be produced from simulated C 2 H 6 /C 2 H 4 (v/v 10/90) mixtures under ambient conditions in a single step, comparable to those of many popular materials.