Heat-resistant TiO2 nanocomposites with anatase phase as carriers for highly efficient CO oxidation catalysts

Abstract

Thermally stable nanocomposites TiO2 with anatase structure doped with ceria or yttria have been synthesized by impregnation method with using a special precursor of titania. All dopants used in this research increase the temperature of anatase to rutile transition and stabilize anatase phase up to 900 °C. In obtained composites calcined at 300-600 °C, microstructural analysis revealed the formation of nanocristalline TiO2 structure consisting of intergrown incoherently 3–8 nm fine anatase particles with the formation of inrerblock boundaries between them. In the region of interblock boundaries the anatase structure is disordered and dopants are localized there in near atomic state. Under the heating at high temperatures, all composites have the rather high surface area and uniform pore diameter. The ceria doped composite was used as support for preparation of 2% Pt/Ce-TiO2 catalyst for CO oxidation. The obtained catalyst demonstrates a high catalytic activity at rather low temperature.