- 作者: 馮銘祥 ; 趙桂蓉
- 作者服務機構: 清華大學化學系
- 中文摘要: The substitution of aluminium for silicon in sodium and proton forms of MFI zeolites has been studied by theoretical force field calculations. The parameters of the cff91_czeo force field developed by Hill and Sauer for zeolites were adopted in this calculation. The molecular structure was optimized according to an energy minimization algorithm with the Newton-Raphson method. The results indicate that there seems little energetic preference for aluminium location in Na-MFI, and that the smaller is the Si-O-Al angle, the smaller is the proton-aluminium substitution energy in H-MFI. The acidity is related to the framework structure and the strong acid sites are correlated with large Si-O-Al angles. These conclude that the electrostatic interaction plays a minor role in aluminium substitution and the locations of aluminium atoms and of Bronsted acid sites depend mainly on the framework geometry.
- 英文摘要: --
- 中文關鍵字: Zeolite; Aluminum Substitution; Theoretical Force Field Calculation; Newton-Raphson Method; Molecular Structure; Electrostatic Interaction
- 英文關鍵字: 沸石;鋁取代;理論力場計算;Newton-Raphson法;分子結構;靜電作用