A process for the preparation of a TiO2-containing catalyst or catalyst support which is stable to high temperatures is described. In this process an aqueous Ti-containing solution having a concentration of dissolved Ti equivalent to 10 to 250 g TiO2 per liter of solution is added to a suspension of not more than 10 wt. % strength of a finely disperse inorganic support material in water, the inorganic support material having a specific surface area, measured by the BET method, of >20 m2/g and any primary particle agglomerates present having a particle size of d50