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 the 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.