柠檬酸添加方式对Mo-Ni-P/Al_2O_3催化剂加氢活性的影响

以Mo、Ni为活性组分,Al_2O_3为载体,采用不同柠檬酸添加方法制备了Mo-Ni-P/Al_2O_3催化剂.通过氢气程序升温还原(H2-TPR)、X射线衍射(XRD),透射扫描电镜(TEM)、XPS等表征方法研究催化剂的物化性质.结果表明:催化剂经柠檬酸的后处理,改善了载体氧化铝表面羟基基团的分布,促使Mo物种以八面体配位多核聚钼酸的形态存在,有效地减弱了载体与活性金属之间的强相互作用,提高了Mo物种的分散度与硫化度,使得催化剂形成更多"Mo-Ni-S"加氢活性相,提高了催化剂的加氢活性.与其他处理方法相比,柠檬酸后处理的催化剂对VGO具有更高的加氢脱硫、脱氮与芳烃饱和性能.

Effect of Addition Method of Critric Acid on Hydrogenation Performance of Avtivity of Mo-Ni-P/Al2O3 Catalyst

Mo-Ni-P/Al₂O₃ catalyst was prepared by loading Mo-Ni metals on Al₂O₃ support, treated by different citric acid addition methods. The physicochemical properties of the catalysts were characterized by H₂-TPR, XRD, TEM and XPS. The results show that the treatment not only promotes Mo species to form octahedral coordinated multi-core plyoxomolybdate acid, improving the distribution of hydroxyl on the Al₂O₃ support surface, but also increases the dispersion and sulfidation degree of Mo species on the Mo-Ni-P/Al₂O₃ catalyst by weakening the interaction between Al₂O₃ support and active metals, resulting in more "Mo-Ni-S" active phase and higher hydrogenation performance. Compared with the catalyst prepared by other methods with citric acid, the catalyst of post-treated with glycol solution shows higher HDS, HDN and aromatics saturation performance than other methods catalysts for VGO.