Abstract: The mass transfer process of traditional titanium silicalite zeolite(TS-1) is limited due to its microporous characteristics. The crystal growth orientation and morphology of TS-1 can be controlled by introducing polyvinyl alcohol (PVA) as a structure directing agent. DTS-t zeolite with different crystallization time were prepared by dynamic hydrothermal crystallization method. Furthermore, under the same sol system, the dynamic crystallization 3 h sample without PVA (N-DTS-3) and the traditional TS-1 zeolite with PVA (CTS-48) were prepared. The material properties were characterized by XRD, SEM, TEM, N₂ adsorption desorption, FT-IR, UV-vis and XPS. The results show that DTS-3 prepared by adding PVA can form a complete crystal structure within 3 h; DTS-t zeolite has a particle size of about 1μm, a total specific surface area of more than 430 m²/g, a microporous specific surface area of about 400 m²/g, and no anatase TiO₂. The catalytic oxidative desulfurization performance of 1000 mg/L thiophene/n-octane as simulated oil was tested. The results showed that for DTS-6 zeolite with the best catalytic performance at 60 ℃, the catalytic oxidative desulfurization rate reached 90% at 60 min, and increased to 95.1% at 110 min. the desulfurization rate was 20% and 6% higher than that of N-DTS-3 zeolite and traditional CTS-48 zeolite, respectively. The introduction of PVA significantly improved the mass transfer efficiency of TS-1.

Key words: titanium silicalite zeolite, polyvinyl alcohol, dynamic crystallization, oxidative desulfurization