Ni_2P/TiO_2-Al_2O_3催化剂的制备及其加氢脱硫、脱氮性能

采用溶胶-凝胶法制备了TiO2-Al2O3复合载体,采用浸渍法制备了Ni2P/TiO2-Al2O3催化剂,并用X射线衍射(XRD)、N2吸附比表面积(BET)测定、热重-差热分析(TG-DTA)、X射线光电子能谱(XPS)等技术对催化剂的结构和性质进行了表征.催化剂加氢脱硫(HDS)和脱氮(HDN)活性评价在实验室固定床连续反应装置上,以噻吩和吡啶为模型反应物进行.考察了不同载体、Ni2P负载量、标称Ni/P摩尔比、催化剂焙烧温度对Ni2P/TiO2-Al2O3催化剂上同时进行的噻吩加氢脱硫和吡啶加氢脱氮性能的影响.结果表明,TiO2含量为80%(w)的TiO2-Al2O3复合氧化物为载体,Ni2P负载量为30.0%(w),标称Ni/P摩尔比为1/2,催化剂焙烧温度为500℃时,Ni2P/TiO2-Al2O3催化剂加氢脱硫脱氮活性最高.在360℃,3.0MPa,氢油比800(V/V),液时体积空速1.5h-1的条件下,噻吩HDS和吡啶HDN转化率分别为61.32%和64.43%.

Preparation, Hydrodesulfurization and Hydrodenitrogenation Performance of a Ni2P/TiO2-Al2O3 Catalyst

We prepared a TiO₂-Al₂O₃ complex support by the sol-gel method. A nickel phosphide catalyst, Ni₂P/ TiO₂-Al₂O₃, was prepared by the impregnation method. The catalysts were characterized by X-ray diffraction (XRD), N₂-adsorption specific surface area measurements (BET), thermogravimetry-differential thermal analysis (TG-DTA), and X-ray photoelectron spectroscopy (XPS). The catalysts were evaluated using a lab-scale continuous flow fixed-bed reactor for simultaneously hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) of thiophene and pyridine. The effects of different supports, Ni₂P loading, Ni/P molar ratio, and calcination temperature on catalyst activity for the HDS and HDN were studied. The catalytic activity of the Ni₂P/TiO₂-Al₂O₃ catalyst with a TiO₂ mass fraction of 80%, a Ni₂P loading of 30.0%(w), a Ni/P molar ratio of 1/2 as well as a calcination temperature of 500^oCwas found to be optimal. At a reaction temperature of 360 ^o, a pressure of 3.0 MPa, a hydrogen/oil ratio of 800 (V/V), and a liquid hourly space velocity of 1.5 h^-1, the conversion of thiophene HDS and pyridine HDN were 61.32%and 64.43%, respectively.