ABSTRACT
This chapter discusses the effect of support, especially TiO2 and Ti containing mixed oxides with special reference to distillate fuel hydrotreating. Support plays important role in many heterogeneous catalytic reactions including hydrodesulfurization and related reactions. Use of Γ–Al2O3 based support is not only due to favourable catalytic properties but also due to suitable physico-chemical and mechanical properties. SiO2 supported Mo and C0M0 catalysts are one of the earliest catalysts that received considerable attention not so much for their commercial potential but for the contrast they provide in comparison with γ-Al2O3 supported catalysts. TiO2 supported systems exhibited higher activities compared to Al2O3 supported Mo and CoMo systems. However thermal instability, low surface area and poor mechanical properties came in their way of commercial exploitation. The TPR studies indicated that mixed oxide supported catalysts are intermediate in reduction behaviour between Al and Ti. This chapter suggests that both Ti and Al ions are involved in binding the supported molybdenum.
