Crystallization-controlled microstructure of titanium species in TS-1 zeolite for tailored catalytic performance

Abstract

TS-1 zeolite, celebrated for its superior catalytic performance in selective oxidation reactions, presents a significant challenge in optimizing the microstructure of its titanium active sites to maximize efficiency for specific applications. In this study, we successfully manipulated the microstructure of titanium species within TS-1 by kinetically controlling the crystallization process, thereby achieving the formation of poly-hexacoordinated Ti species in the initial amorphous titanosilicate phase and the construction of framework TiO₄ species in fully crystallized TS-1 zeolite. Notably, the amorphous titanosilicate catalyst exhibited high efficiency in the oxidative desulfurization of dibenzothiophene, while showing negligible activity in 1-hexene epoxidation. Conversely, the crystalline TS-1 catalyst demonstrated outstanding performance in alkene epoxidation but limited efficacy in oxidative desulfurization. This study outlines a controlled crystallization process that allows precise tuning of zeolite active sites, thereby enhancing their catalytic effectiveness for targeted applications.