Abstract:

A series of hydrogenation catalysts with γ-Al₂O₃ and phosphorus-modified γ- Al₂O₃ as the carrier and Ni and W as the active metal components were prepared by the equal volume impregnation method. The supports and catalysts were characterized with N₂ adsorption-desorption, XRD, NH₃-TPD and Py- IR. The phosphorus modification effects on the properties of hydrogenation catalysts were examined, and the relationship between adsorption behavior of quinoline, indole, dibenzothiophene(DBT) and the catalysts properties as well as the properties of the adsorbate itself were investigated. The results indicated that quinoline was the most easily adsorbed on Al₂O₃ catalysts and phosphorus-modified Al₂O₃ catalysts, while the adsorption capacity of indole and DBT was almost the same. The catalysts modified by phosphorus showed smaller specific surface area and pore volume, but on which the adsorption capacity of quinoline, indole and DBT was promoted. The adsorption capacity of sulfur and nitrogen compounds on the catalysts increased with the increase of the catalyst surface acidity or the acid site quantities and the increase of the active metal dispersion, as well as the increase of the heteroatom electron cloud density or molecular polarity of the sulfur and nitrogen compounds.

Key words: catalyst, hydrogenation, alumina, phosphorus, sulfur and nitrogen compound, adsorption

摘要：

采用等体积浸渍法制备了一系列以γ-Al₂O₃及磷改性γ-Al₂O₃为载体，Ni、W为活性金属组分的加氢催化剂，以N₂物理吸附-脱附、XRD、NH₃-TPD、Py-IR等技术对Al₂O₃及P/Al₂O₃系列催化剂进行了表征，考察了磷改性对加氢催化剂理化性质的影响，探究了喹啉、吲哚和二苯并噻吩（DBT）吸附行为与催化剂理化性质以及吸附质本身性质的关系。研究发现，喹啉最易于吸附在Al₂O₃及P/Al₂O₃系列催化剂上，吲哚和DBT的吸附能力较为接近；磷的引入会降低催化剂的比表面积和孔体积，但是能够提高喹啉、吲哚及DBT的吸附能力；硫氮化合物在催化剂上的吸附能力随着催化剂表面酸性的增强或酸中心数量的增多、活性金属分散度的增大以及硫氮化合物杂原子电子云密度或分子极性的增大而增大。

关键词: 催化剂, 加氢, 氧化铝, 磷, 硫氮化合物, 吸附