准“原位”XPS技术研究加氢精制催化剂的硫化过程

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

用准“原位”XPS技术研究了Mo／Al2O3、Mo／TiO2－Al2O3、CO／Al2O3、CO／TiO2－Al2O3、Co－Mo／Al2O3和Co－Mo／TiO2－Al2O3等催化剂的硫化过程．结果表明：对以Al2O3为载体的催化剂，当Mo或Co载量较低（分别低于0．05gMoO3／gAl2O3或0．03gCoO／gAl2O3）时，没有Mo或Co硫化物的生成，而以TiO2改性的Al2O3为载体的催化剂，Mo／TiO2－Al2O3催化剂的硫化较Mo／Al2O3容易得多,表现为在较低温度下，负载在TiO2改性Al2O3载体上的MoO3，能很快硫化并达到相当大的硫化度,对Co／Al2O3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Co3O4微晶的硫化却容易得多,载体用TiO2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Co3O4微晶的硫化．噻吩加氢脱硫（HDS）的活性测量指出，对Co-Mo／Al2O3和Co－Mo／TiO2－Al2O3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TiO2改性载体，可以增加Co－Mo催化剂的HDS活性和硫化度．

The suffidation process of Mo/Al2O3, Mo/TiO2-Al2O3, Co/Al2O3 t Co/TiO2Al2O3, Co-Mo/Al2O3 and Co-Mo/TiO2-Al2O3 samples were studied by using 'in - situ'XPS techniques.The results show that for alumina-supported catalysts with lower Mo orCo loading (less than 0.05g MoO3/gAl2O3 or 0.03g CoO/gAl2O3 respectively) the Mo andCo sulfides can not be formed. While the catalysts supported on the TiO2-modified aluAnna, the sulfidatrion of Mo/TiO2-Al2O3 catalysts is much easier than that of Mo/Al2O3catalysts. The highly dispersed cobolt oaldic species are very difficult to the Co/Al2O3catalysts be sulfided even at 400℃, while the sulfidation of Co3O4 crystallite is much easier. The TiO2-modified alumina does not affect the sulfidation of the Co/Al2O3 of the Co/Al2O3 catalystsin the form of higher dispersion, but has a significant inIluence on the samdation of Co3O4crystalhte. The activity measuxements of thiophene hydrodesulfUIization (HDS) indicatethat a good correlation exists between the degree of sffodation and HDS activity for bothCo-Mo/AlzOa and Co-MP/TiO2-Al2O3 catalysts. The HDS activity and samdation de-gree of Co-Mo catalysts can be increased remarkly as using the TiO2-modified aluminacarrier.