Efficient ethylene purification by a robust ethane-trapping porous organic cage

The removal of ethane (C2H6) from its analogous ethylene (C2H4) is of paramount importance in the petrochemical industry, but highly challenging due to their similar physicochemical properties. The use of emerging porous organic cage (POC) materials for C2H6/C2H4 separation is still in its infancy. Here, we report the benchmark example of a truncated octahedral calix[4]resorcinarene-based POC adsorbent (CPOC-301), preferring to adsorb C2H6 than C2H4, and thus can be used as a robust absorbent to directly separate high-purity C2H4 from the C2H6/C2H4 mixture. Molecular modelling studies suggest the exceptional C2H6 selectivity is due to the suitable resorcin[4]arene cavities in CPOC-301, which form more multiple C-H hydrogen bonds with C2H6 than with C2H4 guests. This work provides a fresh avenue to utilize POC materials for highly selective separation of industrially important hydrocarbons. The removal of ethane from ethylene is of importance in the petrochemical industry, but similar physicochemical properties of these molecules makes separation a challenging task. Here, the authors demonstrate that a robust octahedral calix[4]resorcinarene-based porous organic cage can separate high-purity ethylene from ethane/ethylene mixtures.

Automated summary

The study presents a porous organic cage based on truncated octahedral calix[4]resorcinarene that can efficiently separate high-purity ethylene from ethane/ethylene mixtures.