Relationships between microstructure of metal-organicframeworks and their adsorption properties

Autor: Yen-Ru Chen, 陳彥儒
Rok vydání: 2017
Druh dokumentu: 學位論文 ; thesis
Popis: 105
MIL-100(Fe) is a metal-organic framework which has significant water adsorption capacity. However, the structural stability for water vapor adsorption was found to be reduced if hydrofluoric acid (HF), served as mineralizing agent, is not used in the synthesis, although preferred because of eco-friendly consideration. We investigated the structural stability for water vapor adsorption of MIL-100(Fe) via density functional theory and molecular simulation techniques. Dreiding force field for MIL-100(Fe) and TIP4P for water were used in this study, and water adsorption isotherm showed improved consistency of results with experiment. We then differenced three kinds of terminal anions (fluoride, hydroxide, and void, i.e., no ion) on the structural stability for water vapor adsorption of MIL-100(Fe). We found that the replacement of hydroxide group would raise the energy of cluster by over 210 eV. Ideal MIL-100(Fe) with alternative anion (Cl and OH) show poor water adsorption capacity while the interacting energy of defective structure show significant increase at low loading region, which might enhance the water adsorption capacity. Further investigation into this interesting defective structure may lead to future use of catalyst, separation, or even the gate dielectrics in ICs.
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