A practicable mesostructured MFI zeolitic catalyst for large molecule reactions
•A stable mesostructured MFI zeolite is used in the large molecule reaction.•Almost all of the acid sites are located on the external surface of the zeolites.•Brönsted and Lewis acid sites are favorable for the benzylation of bulk molecules.•High activity and stability of the catalyst are also from low diffusion limitation.
A microspherical mesostructured zeolite (MMZ-5) with MFI-topological frameworks is employed. In-situ FT-IR spectra of pyridine and 2, 6-di-tert-butylpyridine have indicated that almost all of the acid sites are located on the zeolitic external surface, which are favorable for access of reactive large molecules. This key effect, along with the reduced diffusion and steric limitation, has been proposed to be main the reason for the enhanced catalytic activity, selectivity and stability exhibited in benzylation of aromatics with benzyl chloride. The need for optimized characterization of the mesoporous surface acidity for different aromatics is highlighted.
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Journal: Catalysis Communications - Volume 78, 10 March 2016, Pages 68–70