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

作者：Yang Jing; Sun Huai^*

来源：Science in China Series B-Chemistry, 2009, 52(3): 282-287.

DOI：10.1007/s11426-009-0053-8

• density functional theory
• P-ZSM-5 zeolite
• dealumination
• NMR

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 phosphorus 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 Al-27 NMR chemical shifts for the obtained structures are consistent with the experimental measurements.

• 出版日期2009-3
• 单位上海交通大学