准“原位”XPS技术研究加氢精制催化剂的硫化过程

用准“原位”XPS技术研究了Mo/Al_2O_3、Mo/TiO_2-Al_2O_3、CO/Al_2O_3、CO/TiO_2-Al_2O_3、Co-Mo-Al_2O_3和Co-Mo/TiO_2-Al_2O_3等催化剂的硫化过程．结果表明：对以Al_2O_3为载体的催化剂，当Mo或Co载量较低(分别低于0.05 gMoO_3/gAl_2O_3或0.03gCoO/gAl_2O_3)时，没有Mo或Co硫化物的生成，而以TiO_2改性的Al_2O_3为载体的催化剂，Mo/TiO_2-Al_2O_3催化剂的硫化较Mo/Al_2O_3容易得多, 表现为在较低温度下，负载在TiO_2改性Al_2O_3载体上的MoO_3，能很快硫化并达到相当大的硫化度, 对Co/Al_2O_3催化剂而言，即使在较高温度400 ℃时，载体上高分散的CoO物种仍难以硫化；而Co_3O_4微晶的硫化却容易得多, 载体用TiO_2改性，并不影响高分散形态的CoO催化剂的硫化，却明显地影响Co_3O_4微晶的硫化．噻吩加氢脱硫(HDS)的活性测量指出，对Co-Mo/Al_2O_3和Co-Mo/TiO_2-Al_2O_3催化剂而言，HDS活性和硫化度之间存在着良好的相关性．并用TiO_2改性载体，可以增加Co-Mo催化剂的HDS活性和硫化度.

Investigation of Sulfidation Processes for Hydrotreating Catalysts by "in-situ" XPS Technique

The suffidation process of Mo/Al_2O_3, Mo/TiO_2-Al_2O_3, Co/Al_2O_3 t Co/TiO_2Al_2O_3, Co-Mo/Al_2O_3 and Co-Mo/TiO_2-Al_2O_3 samples were studied by using "in - situ" XPS techniques. The results show that for alumina-supported catalysts with lower Mo orCo loading (less than 0.05 g MoO_3/gAl_2O_3 or 0.03 g CoO/gAl_2O_3 respectively) the Mo andCo sulfides can not be formed. While the catalysts supported on the TiO_2-modified aluAnna, the sulfidatrion of Mo/TiO_2-Al_2O_3 catalysts is much easier than that of Mo/Al_2O_3catalysts. The highly dispersed cobolt oxidic species are very difficult to the Co/Al_2O_3 catalysts be sulfided even at 400 ℃, while the sulfidation of Co_3O_4crystallite is much easier. The TiO_2-modified alumina doed not affect the sulfidation of the Co/Al_2O_3 catalysts in the form of higher dispersion, but has a significant influence on the sulfidation of Co_3O_4 crystallite. The activity measurements of thiophene hydrodesulfurization (HDS) indicate that a good correlation exists between the degree of sulfidation and HDS activity for both Co-Mo/Al_2O_3 and Co-Mo/TiO_2-Al_2O_3 catalysts. The HDS activity and sulfidation degree of Co-Mo catalysts can be increased remarkly as using the TiO_2-modified alumina carrier.