Highly Selective Enclathration of Ethylene from Gas Mixtures

Abstract

Hydroquinone (HQ) is known to form clathrate compounds with various gases as guests. In this study, pure ethylene (C2H4), pure ethane (C2H6), and mixtures thereof with various compositions were used at 4.0 MPa and ambient temperature to form clathrate compounds. Spectroscopic results for the HQ samples show highly selective enclathration of C2H4 when HQ is converted into the clathrate compounds. The captured amount of C2H4 is found to increase when the partial pressures of C2H4 in the mixed gases are increased, and is estimated to store 44.5–82.3 L (at STP condition) of C2H4 gases per 1 L of the solid HQ compounds. A combined effect of the guest–host interaction and molecular size of guests on the hydrogen-bonded organic framework of the HQ clathrates may be contributed to this selective enclathration of C2H4 by acting as a molecular sieve.