Methods of preparing a catalyst
A method of preparing a catalyst support comprising contacting an acid-soluble titanium-containing compound with an acid to form a first mixture; contacting the first mixture with an alkali metal silicate to form a hydrogel which has a silica content of from about 18 wt. % to about 35 wt. % based on the total weight of the hydrogel; contacting the hydrogel with an alkaline solution to form an aged hydrogel; washing the aged hydrogel to form a washed hydrogel; and drying the washed hydrogel to produce a titanium-containing-silica support wherein the support has a pore volume equal to or greater than about 1.4 cm 3 /g.
1. A titanium-containing hydrogel composition comprising:
a) a hydrogel having a silica content of from 18 wt. % to 35 wt. % based on a total weight of the hydrogel;
b) water; and
c) titanium.
2. The titanium-containing hydrogel composition of claim 1 , wherein an amount of titanium is in a range of from about 0.1 wt. % to about 10 wt. % based upon the total weight of the hydrogel.
3. The titanium-containing hydrogel composition of claim 2 having a pH of less than about 6.
4. The titanium-containing hydrogel composition of claim 2 , further comprising chromium in an amount ranging from about 0.1 wt. % to about 10 wt. % based upon the total weight of the hydrogel.
5. The titanium-containing hydrogel composition of claim 1 having a pH of less than about 6.
6. The titanium-containing hydrogel composition of claim 1 , further comprising chromium in an amount ranging from about 0.1 wt. % to about 10 wt. % based upon the total weight of the hydrogel.
7. A hydrogel produced by a reactant composition comprising:
a) an acid-soluble titanium-containing compound;
b) an alkali metal silicate;
c) water; and
d) an acid, and
having a silica content of from 18 wt. % to 35 wt. % based on a total weight of the hydrogel.
8. The hydrogel of claim 7 , wherein:
a) the acid-soluble titanium-containing compound is selected from the group consisting of trivalent titanium, tetravalent titanium, titania, and any combination thereof;
b) the alkali metal silicate comprises sodium silicate; and
c) the acid is selected from the group consisting of hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, perchloric acid, sulfamic acid, and any combination thereof.
9. A hydrogel produced by process comprising:
contacting an acid-soluble titanium-containing compound with an acid to form a first mixture; and
contacting the first mixture with an alkali metal silicate to form the hydrogel having a silica content of from 18 wt. % to 35 wt. % based on a total weight of the hydrogel wherein contacting the first mixture with the alkali metal silicate to form a hydrogel occurs at a pH of less than 4.
10. The hydrogel of claim 9 , wherein the alkali metal silicate comprises sodium silicate; wherein the acid-soluble titanium-containing compound comprises trivalent titanium, tetravalent titanium, titania, or combinations thereof; and wherein the acid comprises a mineral acid.
11. The hydrogel of claim 9 , wherein the process for producing the hydrogel further comprises:
contacting the hydrogel with an alkaline solution to form an aged hydrogel;
and washing the aged hydrogel to form a washed hydrogel.
12. The hydrogel of claim 11 , wherein the alkaline solution comprises sodium hydroxide, ammonium hydroxide, sodium metasilicate, tetra-alkyl ammonium hydroxide, potassium hydroxide or combinations thereof.
13. The hydrogel of claim 11 , wherein the alkaline solution has a pH of from about 8 to about 13.
14. The hydrogel of claim 11 , wherein the aged hydrogel has a surface area of less than about 60% of a surface area of the hydrogel.
15. The hydrogel of claim 11 , wherein the titanium is present in an amount of from 0.1 wt. % to about 10 wt. % based on a total weight of the hydrogel.
16. The hydrogel of claim 11 , wherein the process for producing the hydrogel further comprises contacting the hydrogel with a chromium-containing compound to form a chrominated-titanium-containing hydrogel.
17. The hydrogel of claim 16 , wherein the chromium is present in an amount of from about 0.01 wt. % to about 10 wt. % based on a total weight of the hydrogel.
18. A hydrogel produced by a reactant composition comprising:
a) an acid-soluble titanium-containing compound;
b) a chromium-containing compound;
c) an alkali metal silicate;
d) water; and
e) an acid;
having a silica content of from 18 wt. % to 35 wt. % based on a total weight of the hydrogel.
19. The hydrogel of claim 18 , wherein the alkali metal silicate comprises sodium silicate; wherein the acid-soluble titanium-containing compound comprises trivalent titanium, tetravalent titanium, titania, or combinations thereof; and wherein the acid comprises a mineral acid.
20. The hydrogel of claim 18 , wherein the chromium is present in an amount of from about 0.1 wt. % to about 10 wt. % based on a total weight of the chrominated-titanium-containing silica.