Influence of grain size of acidic NiMo/TS-1 on its catalytic performance for hydrodesulfurization of dibenzothiophenes

Abstract

TS-1 zeolites with different grain sizes were prepared under hydrothermal conditions by tuning the amount of template agent, chelating agent, and temperature, which were further used as supports for the NiMo/TS-1 catalysts. The optimization of synthesis conditions has achieved controllable synthesis of grain sizes from nano-scale to micron-scale. TS-1 with smaller grain sizes possess larger specific surface area, external specific surface area, and pore volume, which can effectively shorten the diffusion path of the sulfide with complex structure. Nano-scale TS-1 has more highly-coordinated Ti species, acting as electronic additives to increase the sulfidation degree of the catalyst. Nano-scale NiMo/TS-1 exhibits higher acidity, which is beneficial for hydrodesulfurization (HDS) reactions. Among the series of NiMo/TS-1 catalysts, NiMo/TS-1 (120 nm) catalyst exhibits the highest dibenzothiophene (DBT, 88.4 %) and 4,6-dimethylbenzothiophene (4,6-DMDBT, 62.1 %) HDS activities.

Keywords

• TS-1 zeolites
• Grain size
• Highly-coordinated Ti
• Hydrodesulfurization
• Dibenzothiophenes