One-step synthesis of anatase-free hollow titanium silicalite-1 by the solid-phase conversion method

Development of economic routes for synthesis of hollow titanium silicalite-1 (TS-1) zeolite is of great importance in industry. However, there are still challenges to synthesize hollow TS-1 zeolite without anatase TiO2. In this work, a one-step strategy without mesoporogen by the solid-phase conversion method was successfully developed to synthesize anatase-free hollow TS-1. The appropriate low amount of TPAOH (TPA/SiO2 = 0.13) and the suitable crystallization temperature (170 °C) can not merely induce the formation of hollow structures, but also enable more titanium to enter the framework. Moreover, the transformation mechanism based on crystallization rate and dissolution rate was proposed according to the investigation of the transformation process. The hollow TS-1 with large cavities exhibits high catalytic activity and recycle stability in 1-hexene epoxidation. The efficient strategy reported in this paper will provide new opportunities for further promoting the industrial application of hollow TS-1.