Preparation of TiO2-Al2O3 Support and Simultaneous Hydrodesulfurization and Hydrodenitrogenation over Ni2P/TiO2-Al2O3 Catalyst

The TiO2-Al2O3 complex support was prepared by the sal-gel method, and the nickel phosphide catalyst, Ni2P/TiO2-Al2O3, was made by impregnation. The catalysts were characterized by X-ray diffraction, N-2 adsorption-desorption, infrared spectroscopy, and X-ray photoelectron spectroscopy. The catalysts were evaluated on a lab-scale continuous-flow fixed-bed reactor for hydrodesulfurization (HDS) of thiophene and hydrodenitrogenation (HDN) of pyridine. The experiments were conducted to further investigate the influence of the support, i.e. the support preparation method, TiO2 content, and support calcination temperature, on the catalyst activity. The results showed that the Ni2P phase appeared only in the catalysts prepared from precursors with Ni/P atomic ratio of 1/2. The catalyst made from TiO2-Al2O3 complex oxide with 80% TiO2 as support, which was prepared by the sol-gel method and calcined at 550 degrees C, exhibited the highest activity for thiophene HDS and pyridine HDN. At reaction temperature of 360 degrees C, pressure of 3.0 MPa, hydrogen/oil volume ratio of 500, and liquid hourly space velocity of 2.0 h(-1), the conversion of thiophene HDS and the conversion of pyridine HDN were 61.3% and 64.4%, respectively.