- 作者: 卜善 ; 劉尚斌
- 作者服務機構: 中央研究院原子與分子科學研究所
- 中文摘要: The Bronsted acidity of the various Si(nAl) sites present in zeolites is evaluated from proton binding energy and LUMO energy calculated by the semiempirical MNDO quantum chemical method. The two calculated energy values both exhibit a linear correlation with the existing Si-29 NMR chemical shift and the IR hydroxyl stretching frequency data. The inter-convertibility between different Si(nAl) sites during an alumination or dealumination process is also evaluated based on the calculated substitution energy. The results indicate that alumination processes are less favorable to occur in zeolites than dealumination processes and the latter is more likely to occur for Si(nAl) clusters that contain the maximum number of aluminum nearest neighbors.
- 英文摘要: --
- 中文關鍵字: Zeolite Cluster Model; Aluminum Substitution; Bronsted Acidity; Mndo Calculation
- 英文關鍵字: 沸石簇模型;鋁取代;Bronsted酸性;MNDO計算法