Forming of High Surface Area TiO2 to Catalyst Supports

The attention which has been payed to the application of TiO2 as a catalyst support has been increasing over the past several years. High surface area titanium dioxides are synthesized by flame hydrolysis or precipitation of TiCl4 or other precursers. The high purity is characteristic of the flame hydrolytic produced TiO2. Formed catalyst supports can be manufactured by extrusion processes using raw materials of both high purity and conventional qualities. Four main steps are normally part of an extrusion process: Kneading, extrusion, drying and calcination. Typical process parameters of each production step are varied. Intermediates and final products are characterized. The Influence of different process conditions and additives on catah/tically important parameters such as internal surface area, pore volume and pore size distribution is discussed. It is shown how crushing strength and attrition resistance can be varied. Special attention is given to the TiO2 phase modification in the formed product. It can be varied from mainly anatase via different anatase-rutile-ratios to pure rutile. Using formed TiO2 catalyst supports, precious metal catalysts show new catalytic properties in selective hydrogenation.