Mesoporous amorphous oxide of titanium
View Patent ↗This disclosure provides a process for preparing mesoporous amorphous hydrous oxide of titanium, comprising formation of a precipitate comprising an ionic porogen and a hydrolyzed compound comprising titanium from an aqueous mixture in the pH range of 5 to 10; and removing the ionic porogen from the precipitate to recover a mesoporous hydrous oxide of titanium, the ionic porogen being in sufficient amount and the conditions of precipitating being effective for producing a mesoporous hydrous oxide of titanium having a surface area of at least about 400 m 2 /g and a pore volume of at least 0.4 cc/g.
1. A process for making a mesoporous amorphous hydrous oxide of titanium, comprising:
formation of a precipitate comprising an ionic porogen and a hydrolyzed compound comprising titanium from an aqueous mixture in the pH range of 5 to 10; and
removing the ionic porogen from the precipitate to recover a mesoporous hydrous oxide of titanium, the ionic porogen being in sufficient amount and the conditions of precipitating being effective for producing a mesoporous hydrous oxide of titanium having a surface area of at least about 400 m 2 /g and a pore volume of at least about 0.4 cc/g.
2. The process of claim 1 wherein the ionic porogen is a halide salt.
3. The process of claim 1 wherein the ionic porogen is ammonium chloride.
4. The process of claim 2 wherein the halide salt is ammonium halide, tetramethyl ammonium halide or tetraethyl ammonium halide or mixtures thereof.
5. The process of claim 1 wherein the ionic porogen is removed by washing.
6. The process of claim 1 wherein the oxide of titanium further comprises a dopant.
7. The process of claim 1 wherein the hydrolyzed compound comprising titanium is derived from titanium tetrachloride, titanium oxychloride or mixture thereof.
8. The process of claim 1 wherein at least 2 moles of the ionic porogen precipitates for each mole of the hydrolyzed compound comprising titanium that precipitates.
9. The process of claim 1 or 8 wherein the ionic porogen is a halide salt and at least 3 moles of the halide salt precipitates for each mole of the hydrolyzed compound comprising titanium that precipitates.
10. The process of claim 1 or 8 wherein the ionic porogen is a halide salt and at least 4 moles of the halide salt precipitates for each mole of the hydrolyzed compound comprising titanium that precipitates.
11. The process of claim 1 wherein the pH range is between 6 and 8.
12. A process for making a mesoporous amorphous oxide of titanium, comprising:
precipitating an ionic porogen and a hydrous oxide of titanium in the pH range 5 to 10 from a reaction mixture comprising a titanium starting material, a base and a solvent, wherein the titanium starting material or the solvent, or both, are a source of the anion for the ionic porogen and the base is the source of the cation for the ionic porogen, the precipitating being carried out under conditions effective for recovering a mesoporous oxide of titanium having a surface area of at least about 400 m 2 /g and a pore volume of at least about 0.4 cc/g after removing the ionic porogen from the precipitate.
13. The process of claim 12 wherein the ionic porogen is a halide salt.
14. The process of claim 12 wherein the ionic porogen is ammonium chloride.
15. The process of claim 13 wherein the halide salt is ammonium halide, tetramethyl ammonium halide or tetraethyl ammonium halide or mixture thereof.
16. The process of claim 12 wherein the ionic porogen is removed by washing.
17. The process of claim 12 wherein the titanium starting material is titanium tetrachloride, titanium oxychloride, or mixture thereof.
18. The process of claim 12 wherein the base is ammonium hydroxide, ammonium carbonate, ammonium bicarbonate, tetramethyl ammonium hydroxide or tetraethyl ammonium hydroxide or mixture thereof.
19. The process of claim 12 wherein the solvent is ethanol, n-propanol, i-propanol, dimethyl acetamide, alcoholic ammonium halide and aqueous ammonium halide or mixture thereof.
20. The process of claim 12 wherein the reaction mixture is formed by the steps, in order, of contacting the base and the solvent to form a solution or a mixture and adding the titanium starting material to the solution or mixture.
21. The process of claim 12 wherein the reaction mixture is formed by contacting the titanium starting material and the solvent to form a solution or a mixture and adding the base to the solution or mixture.
22. The process of claim 13 wherein more than about 50 weight percent of the halide salt precipitates from the reaction mixture, the weight percent based on the total amount of the halide salt that can form from the reaction mixture.
23. The process of claim 12 wherein the ionic porogen is a halide salt and more than about 70 weight percent of the halide salt precipitates from the reaction mixture, the weight percent based on the total amount of the halide salt that can form from the reaction mixture.
24. The process of claim 12 wherein the ionic porogen is a halide salt and more than about 90 weight percent of the halide salt precipitates from the reaction mixture, the weight percent based on the total amount of the halide salt that can form from the reaction mixture.
25. The process of claim 12 wherein the pH range is between 6 and 8.