Methods of preparing a polymerization catalyst

1. A method of preparing a catalyst comprising:

contacting a support with a chromium-containing compound and an aqueous solution comprising a trivalent titanium compound to form a catalyst precursor;

drying the catalyst precursor in an inert atmosphere to form a dried catalyst precursor; and

calcining the dried catalyst precursor in an oxidizing atmosphere to produce a catalyst.

2. The method of claim 1 wherein the support comprises an inorganic oxide.

3. The method of claim 1 wherein the support comprises silica.

4. The method of claim 1 wherein the surface area of the support ranges from about 100 m 2 /g to about 1000 m 2 /g.

5. The method of claim 1 wherein the trivalent titanium compound comprises TiCl 3, Ti 2 (SO 4 ) 3, Ti(OAc) 3, Ti(+3) oxylate, Ti (NO 3 ) 3, Ti(+3) lactate or combinations thereof.

6. The method of claim 1 wherein the titanium is present in the catalyst in an amount ranging from about 0.1% to about 10% by weight of the catalyst.

7. The method of claim 1 wherein the chromium-containing compound is a water-soluble compound.

8. The method of claim 1 wherein the chromium is present in the catalyst in an amount ranging from about 0.01% to about 10% by weight of the catalyst.

9. The method of claim 1 wherein the support is contacted with the compound comprising trivalent titanium prior to contact with the chromium-containing compound.

10. The method of claim 1 wherein the support is contacted with the compound comprising trivalent titanium subsequent to contact with the chromium-containing compound.

11. The method of claim 1 wherein the support is simultaneously contacted with the compound comprising trivalent titanium and the chromium-containing compound.

12. The method of claim 1 further comprising calcining the support after addition of the titanium, the chromium, or both.

13. The method of claim 12 wherein the calcining is carried out in a temperature range of from about 400° C. to about 1000° C.

14. A polymerization catalyst as produced by the method of claim 1 .

15. The method of claim 1 further comprising contacting the catalyst with an olefin monomer under suitable polymerization conditions and producing a polymer having an increased high load melt index when compared to a polymer produced using a catalyst prepared with a tetravalent titanium species in aqueous solution.

16. The method of claim 1 further comprising contacting the catalyst with an olefin monomer under suitable polymerization conditions, and producing a polymer having a lower molecular weight when compared to a polymer produced using an a catalyst prepared with a tetravalent titanium species in aqueous solution.

17. The method of claim 1 further comprising contacting the catalyst with an olefin monomer under suitable polymerization conditions and producing a polymer having a broader molecular weight distribution when compared to a polymer produced using a catalyst prepared with a tetravalent titanium species in aqueous solution.

18. The method of claim 1 further comprising contacting the catalyst with an olefin monomer under suitable polymerization conditions and producing a polymer having an increased melt index when compared to a polymer produced using a catalyst prepared with a tetravalent titanium species in aqueous solution.

19. The method of claim 1 wherein the inert atmosphere comprises vacuum, helium, argon, nitrogen gas, or combinations thereof.

20. The method of claim 1 wherein the drying is carried out in a temperature range of from about 25° C. to about 300° C.