TiO_2-Al_2O_3载体的制备及Ni_2P/TiO_2-Al_2O_3催化剂上的同时加氢脱硫和加氢脱氮反应

Preparation of TiO_2-Al_2O_3 Support and Simultaneous Hydrodesulfurization and Hydrodenitrogenation over Ni_2P/TiO_2-Al_2O_3 Catalyst

以溶胶-凝胶法制备的TiO2-Al2O3复合氧化物为载体,采用浸渍法制备了Ni2P/TiO2-Al2O3催化剂,并用X射线衍射、N2吸附脱附、红外和X射线光电子能谱等技术对催化剂进行了表征,考察了载体中TiO2含量、焙烧温度及其制备方法对Ni2P/TiO2-Al2O3催化剂上同时进行噻吩加氢脱硫和吡啶加氢脱氮反应的影响.结果表明,以Ni/P摩尔比为1/2的前驱体制备的催化剂表面仅出现Ni2P物相;当载体中TiO2的含量为80%,焙烧温度为550oC时,Ni2P/TiO2-Al2O3催化剂上加氢脱硫和加氢脱氮的活性最高.在360oC,3.0MPa,氢/油体积比500,液时体积空速2.0h-1的条件下,噻吩和吡啶转化率分别为61.3%和64.4%.

The TiO2-Al2O3 complex support was prepared by the sol-gel method, and the nickel phosphide catalyst, Ni2P/TiO2-Al2O3, was made by impregnation. The catalysts were characterized by X-ray diffraction, N2 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 oC, exhibited the highest activity for thiophene HDS and pyridine HDN. At reaction temperature of 360 oC, 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.