Insights into the Temperature-Dependent “Breathing” of a Flexible Fluorinated Metal-Organic Framework
The framework expansion and contraction upon carbon dioxide uptake was studied in a partially fluorinated metal-organic framework, FMOF-2. The results show framework expansion and contraction (breathing) as a function of pressure and temperature. Even at temperatures as low as -30 ºC, two phase transitions seem to take place with a pressure step (corresponding to the second transition) that is greatly dependent on temperature. This behavior is described by the model proposed by Coudert and co-workers showing that the material seems to undergo two phase transitions that are temperature dependent. The isosteric heats of adsorption at high pressures show a minimum that is concurrent with the region of CO2 loadings where the second pressure step occurs. It was deduced that these lower enthalpy values are a consequence of the energy cost related to the expansion or reopening of the framework. Lastly, the large and reversible breathing behavior may be a product of the combination of the high elasticity of zinc (II) coordination and the apparent high flexibility of the V-shaped organic building block.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1053337
- Report Number(s):
- PNNL-SA-88461; AA7020000
- Journal Information:
- Chemphyschem, 13(14):3275-3281, Journal Name: Chemphyschem, 13(14):3275-3281
- Country of Publication:
- United States
- Language:
- English
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