Preparation of Ni2P/TiO2-Al2O3 and the Catalytic Performance for Hydrodesulfurization of 3-Methylthiophene

Composite TlO2-Al2O3 supports were prepared by the sol-gel technique using tetra-n-butyl-titanate and gamma-Al2O3 as raw materials, and the Ni2P/TiO2-Al2O3 catalysts were obtained by incipient wetness impregnation of aqueous metal phosphate precursors, followed by temperature-programmed reduction of inflowing H-2. The supports and catalysts were characterized by X-ray diffraction, infrared spectroscopy, transmission electron microscopy, and N-2 adsorption. The hydrodesulfurization (HDS) activity was examined in a fixed-bed reactor. Experimental results indicate that the composite support can effectively prevent the formation of aluminum phosphates based on the strong interaction between P and gamma-Al2O3, overcome the disadvantage of low surface titania, and improve metal support interaction, which significantly increase catalyst activity and selectivity. The Ni2P/TiO2-Al2O3 Catalyst exhibits good activity for the HDS of 3-methylthiopliene (3-MT), used as a model compound. The activity and stability of the Ni2P/TiO2-Al2O3 catalyst are affected by the phosphorus content, both achieving a maximum with an initial Ni/P molar ratio of 1:2. The reaction temperature and the weight hourly space velocity (WHSV) show significant influence, but the reaction pressure and the volume ratio of hydrogen/oil have little effect oil the HDS performance of the Ni2P/TiO2-Al2O3 catalyst. The conversion of 3-MT is close to 100% when the reaction temperature reaches 603 K, reaction pressure reaches 2.0 MPa, WHSV reaches 1,275 h(-1), and volume ratio of hydrogen/oil reaches 400.