Acidic aromatization catalyst with improved activity and stability
Methods for producing supported catalysts containing a transition metal and a bound zeolite base are disclosed. These methods employ a step of impregnating the bound zeolite base with the transition metal, fluorine, and high loadings of chlorine. The resultant high chlorine content supported catalysts have improved catalyst activity in aromatization reactions.
1. A supported catalyst comprising:
a bound zeolite base, wherein the bound zeolite base comprises a binder and a large pore zeolite having an average pore diameter in a range of from about 7 Å to about 12 Å;
from about 0.3 wt. % to about 3 wt. % of a transition metal, wherein the transition metal comprises a Group 8-11 transition metal;
from about 1.8 wt. % to about 4 wt. % of chlorine; and
from about 0.4 wt. % to about 1.5 wt. % of fluorine, based on the total weight of the supported catalyst;
wherein the supported catalyst is characterized by a peak reduction temperature on a Temperature Programmed Reduction curve in a range from about 580° F. to about 800° F.
2. The catalyst of claim 1 , wherein the bound zeolite base comprises from about 5 wt. % to about 30 wt. % of the binder, based on the total weight of the bound zeolite base.
3. The catalyst of claim 1 , wherein:
the bound zeolite base comprises a silica-bound K/L-zeolite;
the transition metal comprises platinum; and
a weight ratio of chlorine:fluorine is in a range from about 2:1 to about 5:1.
4. The catalyst of claim 1 , wherein the supported catalyst comprises:
from about 0.5 wt. % to about 2 wt. % of platinum;
from about 2.2 wt. % to about 3.4 wt. % of chlorine; and
from about 0.5 wt. % to about 1.1 wt. % of fluorine.
5. The catalyst of claim 4 , wherein the supported catalyst is characterized by a peak reduction temperature on a Temperature Programmed Reduction curve in a range from about 600° F. to about 720° F.
6. The catalyst of claim 1 , wherein the supported catalyst has a total nitrogen content that is greater than that of an otherwise identical catalyst having from 0.3 wt. % to 1.5 wt. % chlorine.
7. The catalyst of claim 1 , wherein the supported catalyst is characterized by a Temperature Programmed Reduction curve comprising a lower temperature peak and a higher temperature peak, and wherein the higher temperature peak is greater in height than the lower temperature peak.
8. The catalyst of claim 1 , wherein:
the supported catalyst has a platinum dispersion that is substantially the same as that of an otherwise identical catalyst having from 0.3 wt. % to 1.5 wt. % chlorine; and
the supported catalyst has a surface area that is substantially the same as that of an otherwise identical catalyst having from 0.3 wt. % to 1.5 wt. % chlorine.
9. The catalyst of claim 1 , wherein the supported catalyst is characterized by a start of run temperature (T SOR ) in a range from about 915° F. to about 935° F.
10. The catalyst of claim 1 , wherein the supported catalyst further comprises from about 0.6 wt. % to about 1.3 wt. % nitrogen.
11. The catalyst of claim 1 , wherein the supported catalyst is characterized by a peak reduction temperature on a Temperature Programmed Reduction curve that is from about 120° F. to about 300° F. greater than that of an otherwise identical catalyst having from 0.3 wt. % to 1.5 wt. % chlorine.
12. The catalyst of claim 1 , wherein:
the bound zeolite base comprises a silica-bound K/L-zeolite; and
the supported catalyst comprises:
from about 0.7 wt. % to about 1.5 wt. % of platinum;
from about 2 wt. % to about 3.3 wt. % of chlorine; and
from about 0.5 wt. % to about 1.1 wt. % of fluorine.
13. The catalyst of claim 12 , wherein:
the supported catalyst is characterized by a T SOR less than that of an otherwise identical catalyst having from 0.3 wt. % to 1.5 wt. % chlorine, under the same aromatization reaction conditions;
the supported catalyst is characterized by a fouling rate less than that of an otherwise identical catalyst having from 0.3 wt. % to 1.5 wt. % chlorine, under the same aromatization reaction conditions; or
both.
14. The catalyst of claim 12 , wherein the supported catalyst is characterized by an aromatics selectivity that is substantially the same as that of an otherwise identical catalyst having from 0.3 wt. % to 1.5 wt. % chlorine, under the same aromatization reaction conditions.
15. The catalyst of claim 12 , wherein the supported catalyst is characterized by a peak reduction temperature on a Temperature Programmed Reduction curve in a range from about 600° F. to about 720° F.
16. The catalyst of claim 15 , wherein the supported catalyst is characterized by a Temperature Programmed Reduction curve comprising a lower temperature peak and a higher temperature peak, and wherein the higher temperature peak is greater in height than the lower temperature peak.
17. The catalyst of claim 1 , wherein:
the bound zeolite base comprises a silica-bound K/L-zeolite; and
the transition metal comprises platinum.
18. The catalyst of claim 17 , wherein the supported catalyst comprises:
from about 0.7 wt. % to about 1.5 wt. % of platinum;
from about 2 wt. % to about 3.3 wt. % of chlorine; and
from about 0.5 wt. % to about 1.3 wt. % of fluorine.
19. The catalyst of claim 17 , wherein the supported catalyst is characterized by a peak reduction temperature on a Temperature Programmed Reduction curve in a range from about 600° F. to about 720° F.
20. A supported catalyst comprising:
a bound zeolite base, wherein the bound zeolite base comprises a binder and a large pore zeolite having an average pore diameter in a range of from about 7 Å to about 12 Å;
from about 0.7 wt. % to about 1.5 wt. % of platinum;
from about 2 wt. % to about 3.3 wt. % of chlorine; and
from about 0.5 wt. % to about 1.3 wt. % of fluorine, based on the total weight of the supported catalyst;
wherein the supported catalyst is characterized by a peak reduction temperature on a Temperature Programmed Reduction curve in a range from about 600° F. to about 730° F.
21. The catalyst of claim 20 , wherein the supported catalyst further comprises from about 0.4 wt. % to about 1.6 wt. % nitrogen.
22. The catalyst of claim 20 , wherein:
the supported catalyst further comprises from about 0.7 wt. % to about 1.2 wt. % nitrogen; and
the supported catalyst is characterized by a peak reduction temperature on a Temperature Programmed Reduction curve in a range from about 630° F. to about 690° F.