Effect of preparation method and support type on hydrodesulfurization performance of Ni₂P/TiO₂ catalyst

Nickel phosphide catalysts, supported on whiskers and anatase TiO₂, were prepared by temperature programmed reduction method and solvothermal method, respectively. The catalysts were characterized by X-ray diffraction (XRD), N₂-adsorption specific surface area measurements (BET), N₂ adsorption-desorption,CO adsorption, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (TEM). The effects of preparation method and support type on catalyst activity for dibenzothiophene (DBT) hydrodesulfurization (HDS) were studied. The result showed that the structures of the TiO₂ support remained unchanged, and the formation of TiPO₄ was suppressed in solvothermal method process, contributing to higher catalytic activity of Ni₂P/TiO₂ catalysts for HDS than the catalysts obtained by conventional TPR method. Compared with the catalysts supported on anatase TiO₂, the catalysts supported on whiskers TiO₂ displayed excellent surface properties, producing more Ni₂P crystal particles with smaller size and better dispersion, and therefore possessed higher HDS activity. The HDS activity of the catalyst supported on whiskers TiO₂ and made by solvothermal method was found to be the best one among the tested catalysts. The conversion of dibenzothiophene HDS was 98.2% under the selected reaction conditions of 340 ℃, 3.0 MPa, H₂/oil ratio of 500 (volume ratio), and WHSV of 2.0 h^-1.