Synthesis of TS-1 zeolites from a polymer containing titanium and silicon

Abstract

The synthesis of TS-1 zeolites is regarded as a milestone in zeolite history, and it has led to the revolution of the green oxidation system of using H₂O₂ as an oxidant, leaving only water as the byproduct. However, because of the highly hydrolyzable titanium source, the preparation of TS-1 requires complex synthesis conditions. Moreover, the difference in the hydrolysis rate between the silicon source and titanium source tends to increase the difficulty of titanium insertion into the framework, and it is easy to generate extra-framework Ti species during the synthesis. Here, a high-quality TS-1 zeolite with a large external surface area and free of extra-framework Ti species has been successfully synthesized by using a kind of novel polymer containing titanium and silicon. Due to the high hydrolysis resistance of the polymer reagent, a good matching of the hydrolysis rate between the silicon source and the titanium source is realized during crystallization, which facilitates the incorporation of titanium into the framework. Furthermore, the TS-1 zeolite exhibited excellent catalytic performance in n-hexane oxidation with hydrogen peroxide as the oxidant. This method of synthesizing zeolites from polymers is expected to be widely applied for the synthesis of other titanium-containing zeotype materials.