Preparation of Hierarchical Ti-Sil-BEA Zeolite by Silanization Modification for the Application in Dicyclopentadiene Epoxidation Reaction.

The pore-expanding modification of zeolites is an important means to improve their catalytic performance. This study demonstrates the postsynthesis of Ti-Sil-BEA zeolites via silanization-modified parent BEA zeolite and its application in catalyzing epoxidation reactions of dicyclopentadiene (DCPD). The zeolites were characterized by BET, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-vis spectroscopy, and X-ray electron spectroscopy. The impact of silanizing reagents on the crystallization of BEA zeolites as well as pore-expanding was studied. It is revealed that the addition of -[3-(Trimethoxysilyl)-propyl]-ethylenediamine (TSPED) before crystallization of *BEA-type zeolites can effectively introduce mesoporous structures without impacting the integrity of the zeolite crystals (resulting in an augmentation of the mesopore volume by 55% and emergence of mesopores with a diameter of 11 nm). Furthermore, the introduction of TSPED led to the reduction of zeolite size, and the change of the mesoporous structure of Ti-Sil-BEA improved its catalytic performance for the DCPD epoxidation reaction; the DCPD conversion was increased by 11.5%. The dicyclopentadiene dioxide (DCPDDO) selectivity was increased by 52.5%.