CoMo catalyst on zeolite TS-1 nanorod assemblies with high activity in the hydrodesulfurization of 4,6-dimethyldibenzothiophene

Abstract

Crystalline TS-1 zeolite nanorod (NTS-1) assemblies were successfully synthesized. NTS-1 possesses a hierarchically porous structure and a large nanoporous surface area. Following impregnation with Co and Mo species and sulfidation, the obtained catalyst (CoMoS2/NTS-1) shows higher activity in the hydrodesulfurization of refractory 4,6-dimethyldibenzothiophene than the γ-Al2O3, mesoporous zeolite ZSM-5, and Silicalite-1 (MZSM-5 and M-Silicalite-1), as well as binary SiO2–TiO2 supported catalysts. In the absence of mass transfer, the reaction rate constant on CoMoS2/NTS-1 (9.5 × 10−2 μmol∙g−1∙s−1) is much higher than those on CoMoS2/γ-Al2O3, CoMoS2/M-Silicalite-1, CoMoS2/MZSM-5, and CoMoS2/SiO2-TiO2 catalysts (4.2 × 10−2, 7.9 × 10−2, 8.7 × 10−2, and 7.0 × 10−2 μmol∙g−1∙s−1). Characterization results show that the framework Ti species in NTS-1 intensify the interaction of the Mo species with NTS-1, resulting in a sulfided catalyst with a less stacked and shorter MoS2 phase. This exposes more brim sites for hydrogenation, improving the hydrodesulfurization activity of the catalyst.