Home – Home – Jornals – Chemistry for Sustainable Development 2020 number 1

The anatase phase of titanium dioxide TiO₂ is metastable and irreversibly converts to rutile at a temperature above 700 °C. This is accompanied by a significant decrease in the specific surface area and a change in the porous structure. Modification of titanium dioxide by the addition of alumina leads to the formation of the nanocrystalline structure of anatase and to a significant increase in the temperature of anatase to rutile phase transition up to 950 °C. After high-temperature annealing, the Al₂O₃-TiO₂ sample is characterized by a higher specific surface area and a better developed porous structure than those of pure anatase with the regular crystal structure. The high thermal stability of the anatase phase in supported Pt/(Al₂O₃-TiO₂) catalysts under calcination provides a high dispersion of platinum particles, which leads to the rather high catalytic activity of these catalysts in CO oxidation.