Evaluation of the location of Al atoms in zeolite by high resolution 27Al MAS and MQMAS NMR techniques.

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The catalytic properties of aluminosilicate-type zeolites depend on many factors such as pore structure, acid strength and acid amounts. In addition these factors, the location of Al atoms in the zeolite framework has been recognized as an important factor for activity and selectivity, because they would profoundly affect the accessibility of molecules to acid sites and the spatial constraints of the reaction field in the pores; however, their control and evaluation have been difficult to achieve.In this study, In-situ FT-IR spectroscopy using CO as probe molecule was applied to the evaluation of acid property of the ZSM-5 zeolites. The effects of the organic structure-directing agents (OSDAs) and Na cation for the synthesis of ZSM-5 on the location of Al atom in the framework as well as acidic properties and catalytic properties were investigated. I have developed a method for evaluating the location of Al atoms by high resolution 27Al MAS and MQMAS NMR techniques.