Processes for producing fluorided solid oxides and uses thereof in metallocene-based catalyst systems
Disclosed herein are methods for preparing fluorided solid oxides by contacting an acidic fluorine-containing compound with an inorganic base to form an aqueous mixture having a pH of at least 4, followed by contacting a solid oxide with the aqueous mixture to produce the fluorided solid oxide. Also disclosed are methods for preparing fluorided solid oxides by contacting an acidic fluorine-containing compound with a solid oxide to produce a mixture, followed by contacting the mixture with a inorganic base to produce the fluorided solid oxide at a pH of at least about 4. The fluorided solid oxide can be used as an activator component in a catalyst system for the polymerization of olefins.
1. A catalyst composition comprising:
a metallocene compound;
a fluorided solid oxide comprising:
a silica-coated alumina,
from about 0.5 to about 15 wt. % F, and
from about 0.5 to about 15 wt. % Zn,
wherein the fluorided solid oxide comprises ZnSiF 6 ; and
a co-catalyst.
2. The composition of claim 1 , wherein the fluorided solid oxide comprises from about 2 to about 9 wt. % F and from about 0.5 to about 5 wt. % Zn.
3. The composition of claim 1 , wherein the co-catalyst comprises an aluminoxane compound.
4. The composition of claim 1 , wherein the co-catalyst comprises an organoaluminum compound.
5. The composition of claim 4 , wherein:
the silica-coated alumina contains from about 25 to about 50 wt. % silica, based on the weight of the silica-coated alumina; and
the fluorided solid oxide comprises from about 4 to about 10 wt. % ZnSiF 6 .
6. A catalyst composition comprising:
a metallocene compound;
a fluorided solid oxide comprising:
a silica-coated alumina,
from about 0.5 to about 15 wt. % F,
from about 0.5 to about 15 wt. % Zn, and
from about 0.2 to about 1.2 wt. % B; and
a co-catalyst.
7. The composition of claim 6 , wherein the co-catalyst comprises an aluminoxane compound.
8. The composition of claim 6 , wherein the co-catalyst comprises an organoaluminum compound.
9. The composition of claim 6 , wherein the fluorided solid oxide comprises:
from about 3 to about 7 wt. % F;
from about 1 to about 5 wt. % Zn; and
from about 0.3 to about 1 wt. % B.
10. The composition of claim 6 , wherein:
the silica-coated alumina contains from about 25 to about 50 wt. % silica, based on the weight of the silica-coated alumina; and
the fluorided solid oxide has:
a total pore volume from about 0.5 to about 2.5 mL/g;
a BET surface area from about 150 to about 700 m 2 /g; and
an average (d50) particle size from about 20 to about 100 microns.
11. The composition of claim 6 , wherein the metallocene compound is an unbridged metallocene compound.
12. The composition of claim 6 , wherein the metallocene compound is a bridged metallocene compound.
13. The composition of claim 6 , wherein the composition comprises two or more metallocene compounds.
14. A catalyst composition comprising:
a metallocene compound;
a fluorided solid oxide comprising:
a silica-coated alumina, and
Zn(BF 4 ) 2 , ZnSiF 6 , or a combination thereof; and
a co-catalyst.
15. The composition of claim 14 , wherein the fluorided solid oxide comprises Zn(BF 4 ) 2 .
16. The composition of claim 14 , wherein the fluorided solid oxide comprises from about 4 to about 10 wt. % Zn(BF 4 ) 2 .
17. The composition of claim 14 , wherein the fluorided solid oxide comprises ZnSiF 6 .
18. The composition of claim 14 , wherein the fluorided solid oxide comprises from about 4 to about 10 wt. % ZnSiF 6 .
19. The composition of claim 14 , wherein the co-catalyst comprises an aluminoxane compound and/or an organoaluminum compound.
20. The composition of claim 19 , wherein the metallocene compound is an unbridged metallocene compound.
21. The composition of claim 19 , wherein the metallocene compound is a bridged metallocene compound.