Selective Hysteretic Sorption of Light Hydrocarbons in a Flexible Metal-Organic Framework Material

Research output: Contribution to journalArticle

  • External authors:
  • Shan Gao
  • Christopher G. Morris
  • Zhenzhong Lu
  • Yong Yan
  • Harry G. W. Godfrey
  • Claire Murray
  • Chiu C. Tang
  • K. Mark Thomas

Abstract

Porous MFM-202a (MFM = Manchester Framework Material, replacing the NOTT designation) shows an exceptionally high uptake of acetylene, 18.3 mmol g–1 (47.6 wt %) at 195 K and 1.0 bar, representing the highest value reported to date for a framework material. However, at 293 K and 10 bar C2H6 uptake (9.13 mmol g–1) is preferred. Dual-site Langmuir-Freundlich (DSLF)- and Numerical Integration (NI)-based IAST methods have been used to analyze selectivities for C1 to C3 hydrocarbons. MFM-202a exhibits broadly hysteretic desorption of acetylene; such behavior is important for practical gas storage since it allows the gas to be adsorbed at high pressure but stored at relatively low pressure. Stepwise uptake and hysteretic release were also observed for adsorption of other unsaturated light hydrocarbons (ethane and propene) in MFM-202a but not for saturated hydrocarbons (methane, ethane, and propane). MFM-202a has been studied by in situ synchrotron X-ray powder diffraction to reveal the possible phase transition of the framework host as a function of gas loading. A comprehensive analysis for the selectivities between these light hydrocarbons has been conducted using both IAST calculation and dual-component mixed-gas adsorption experiments, and excellent agreement between theory and experiment was achieved.

Bibliographical metadata

Original languageEnglish
Pages (from-to)2331–2340
JournalChemistry of Materials
Volume28
Issue number7
Early online date31 Mar 2016
DOIs
StatePublished - 12 Apr 2016