Oxidation of carbon monoxide over a fibrous titania-supported gold catalyst

Fibrous titania with different micro-structures was prepared from a potassium dititanate whisker precursor by ion exchange and thermal treatment. Gold nanoparticles (1%) were deposited on two fibrous titania supports calcined at 600 and 800°C, respectively, by homogeneous deposition-precipitation. The Au/TiO₂ catalysts were characterized by X-ray diffraction, N₂ adsorption, scanning electron microscopy, transmission electron microscopy, and CO oxidation. The fibrous titania calcined at 600°C had a mesoporous structure, whereas the meso-structure totally collapsed when calcined at 800°C. The crystallinity of the fibrous titania support had a high thermal stability, and the anatase phase was maintained even after calcination at 800°C. The meso-structure of TiO₂ calcined at 600°C was unchanged after deposition of gold particles. Although the particle size of gold on TiO₂ calcined at 600°C was much larger than that on TiO₂ calcined at 800°C, their catalytic performances were comparable.