A theoretical study of hydrothermal stability of P-modified ZSM-5 zeolites

作     者：YANG Jing SUN Huai 

作者机构：School of Chemistry and Chemical TechnologyShanghai Jiao Tong UniversityShanghai 200240China 

出 版 物：《Science China Chemistry》 (中国科学（化学英文版）)

年 卷 期：2009年第52卷第3期

页      面：282-287页

核心收录：

学科分类：081705[工学-工业催化] 08[工学] 0817[工学-化学工程与技术] 

基　　金：Supported by the State Key Development Program of Basic Research of China (Grant No. 2003CB615804) 

主　　题：density functional theory P-ZSM-5 zeolite dealumination NMR 

摘      要：Density functional theory was employed to study the hydrothermal stability of P-modified ZSM-5 zeolites using cluster models. The calculations of hydrolysis energies indicated that the introduction of phos-phorus increases the hydrothermal stability of ZSM-5 zeolites. The initial paths of dealumination were studied with explicit water molecules. It was found that the framework Al-O coordination bond can be replaced by coodination bonds between water molecules and the aluminium. One to three water molecules can form coordination bonds with framework Al and release energies. The P-modification restrain the dealumination. The calculated 27Al NMR chemical shifts for the obtained structures are consistent with the experimental measurements.