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以负载磷酸镍为前驱体采用程序升温还原法制备了Ni_2P/SiO_2催化剂,采用H2-程序升温还原(H_2-TPR)、X-射线衍射(XRD)、透射电子显微镜(TEM)、N_2吸附、CO吸附和NH_3-程序升温脱附(NH_3-TPD)等方法研究了前驱体焙烧温度对Ni_2P/SiO_2催化剂结构和月桂酸甲酯脱氧性能的影响。结果表明,随着前驱体焙烧温度从400℃增加到800℃,所制备催化剂的比表面积、孔容先基本不变然后降低,Ni_2P晶粒尺寸增大,催化剂酸性减弱。在月桂酸甲酯脱氧反应中,随前驱体焙烧温度提高,所制备Ni_2P/SiO_2催化剂脱氧活性先升高后降低,其中由在500℃焙烧前驱体所制备的催化剂具有较高脱氧性能;此外,脱氧产物十一烷和十二烷的物质的量之比呈现先基本不变后减小的趋势,说明前驱体焙烧温度对所制备催化剂上脱氧途径有一定影响。影响脱氧途径的主要因素是Ni_2P晶粒尺寸及催化剂酸性。
Ni 2 P / SiO 2 catalysts were prepared by temperature-programmed reduction using Ni 2+ as the precursor. The catalysts were characterized by H2-temperature programmed reduction (TPR), X-ray diffraction (XRD), transmission electron microscopy (TEM) Adsorption and NH_3-temperature programmed desorption (NH_3-TPD) and other methods to study the precursor calcination temperature Ni_2P / SiO_2 catalyst structure and methyl laurate deoxy performance. The results showed that the specific surface area and pore volume of the prepared catalyst decreased substantially and then decreased with the calcination temperature of the precursor increasing from 400 ℃ to 800 ℃, and the grain size of Ni_2P increased and the acidity of the catalyst decreased. In deacidation of methyl laurate, the deoxygenation activity of Ni 2 P / SiO 2 catalyst firstly increased and then decreased with the calcination temperature of the precursor increasing, and the catalyst prepared by calcination at 500 ℃ had a higher deoxidation performance. In addition, The ratio of the amount of deoxygenated products of undecane to dodecane showed a tendency of decreasing first and then decreasing, indicating that the calcination temperature of the precursors had certain influence on the deoxidation pathway of the prepared catalyst. The main factors affecting the deoxidation pathway are Ni 2 P grain size and catalyst acidity.