Modified titanium dioxide and a method for its preparation
AssigneeRotem Amfert Negev Ltd.
InventorsYaacov W. Mirsky, Marina N Gorlova
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Abstract
The invention relates to a composite material comprising silicon and titanium dioxide characterized by an enhanced thermal and hydrothermal stability of the pore structure. The composite is obtainable by precipitating titanium hydroxide from an aqueous solution containing sulfate salts and urea, followed by an hydrothermal treatment in the mother liquor, and by reacting the precipitate with a basic silica sol. The composite has a specific surface area of up to 228 m2/g for a material calcined at 800° C. for 3 hours, and is suitable for catalyzing a variety of reactions, including Claus reaction and degradation of organic impurities.
Claims16
A method for preparing silicon-containing titanium dioxide, comprising the steps of:
- a) precipitating titanium hydroxide from an aqueous solution containing dissolved sulfate salts, including titanyl sulfate, in the presence of urea;
- b) heating the precipitate in its aqueous mother liquor at a temperature in a range of between 70° C. to 200° C.;
- c) separating said titanium hydroxide precipitate from the solution and washing the same;
- d) reacting the precipitate, or a dried titanium dioxide obtained therefrom, with a basic silica sol to produce silicon-containing titanium hydroxide or silicon-containing titanium dioxide, and, in the case of silicon-containing titanium hydroxide, converting the same to silicon-containing dioxide.
A method for preparing silicon-containing titanium dioxide, comprising:
- a) providing titanium hydroxide or titanium dioxide in the form of a dough, paste, suspension or wet cake;
- b) bringing the pH of said titanium hydroxide or titanium dioxide to a value in the range between 6.0 to 11;
- c) reacting said titanium hydroxide or titanium dioxide with basic silica sol, to obtain silicon-containing titanium hydroxide or silicon-containing titanium dioxide, and, in the case of silicon-containing titanium hydroxide, converting the same to silicon-containing titanium dioxide.
Dependencies are inferred from the claim text.