Dehydrogenation catalysts and methods for preparing and using them
This disclosure relates to catalysts comprising gallium, cerium, and a mixed oxide support useful in the dehydrogenation of hydrocarbons, to methods for making such catalysts, and to methods for dehydrogenating hydrocarbons with such catalysts. For example, in one embodiment, a catalyst composition includes gallium oxide, present in the composition in an amount within the range of about 0.1 wt. % to about 30 wt. %, cerium oxide, present in the composition in an amount within the range of about 0.1 wt. % to about 15 wt. %, a promoter, M1, selected from Pt, Ir, La, or a mixture thereof, present in the composition in an amount within the range of about 0.005 wt. % to about 4 wt. %, a promoter, M2, selected from the group 1 elements (e.g., Li, Na, K, Cs), present in the composition in an amount within the range of about 0.05 wt. % to about 3 wt. %, and a support, S1, selected from alumina, silica, zirconia, titania, or a mixture thereof, present in the composition in an amount within the range of about 60 wt. % to about 99 wt. %.
1. A calcined dehydrogenation catalyst composition comprising
gallium oxide, present in the composition in an amount within the range of about 1 wt. % to about 20 wt. %, calculated as Ga 2 O 3 on a calcined basis;
cerium oxide, present in the composition in an amount within the range of about 0.1 wt. % to about 10 wt. %, calculated as CeO 2 on a calcined basis;
a promoter M1 selected from platinum, iridium, lanthanum, or a mixture thereof, present in the composition in an amount within the range of about 0.01 wt. % to about 2 wt. %, calculated as oxide on a calcined basis;
a promoter M2 selected from the group 1 elements, present in the composition in an amount within the range of about 0.05 wt. % to about 3 wt. %, calculated as oxide on a calcined basis; and
a support S1 selected from alumina, silica, zirconia, titania, or a mixture thereof, present in the composition in an amount within the range of about 60 wt. % to about 99 wt. %, calculated as oxide on a calcined basis.
2. The catalyst composition of claim 1 , wherein M1 includes Ir.
3. The catalyst composition of claim 1 , wherein M1 is present in the composition in an amount within the range of about 0.01 wt. % to about 1 wt. %, calculated as oxide on a calcined basis.
4. The catalyst composition of claim 1 , wherein M2 is selected from Li, Na, K, and Cs.
5. The catalyst composition of claim 1 , wherein M2 is present in the composition in an amount within the range of about 0.05 wt. % to about 2 wt. %, calculated as oxide on a calcined basis.
6. The catalyst composition of claim 1 , further comprising a promoter M1-B selected from Sn and Pd, present in the composition in an amount within the range of about 0.005 wt. % to about 0.5 wt. %, calculated as SnO 2 or PdO, respectively, on a calcined basis.
7. The catalyst composition of claim 1 , further comprising a promoter M3 selected from Mg, Ca, Sr, Ba, Fe, Co, and Ni, present in the composition in an amount within the range of about 0.05 wt. % to about 10 wt. %, calculated as oxide on a calcined basis.
8. The catalyst composition of claim 7 , wherein M3 is selected from Mg and Ca, and is present in the composition in an amount within the range of about 0.05 wt. % to about 7 wt. %.
9. The catalyst composition of claim 1 , wherein
gallium oxide is present in the composition in an amount within the range of about 2 wt. % to about 15 wt. %, calculated as Ga 2 O 3 on a calcined basis;
cerium oxide is present in the composition in an amount within the range of about 0.1 wt. % to about 3 wt. %, calculated as CeO 2 on a calcined basis;
M1 is present in the composition in an amount within the range of about 0.01 wt. % to about 1 wt. %, calculated as oxide on a calcined basis; and
M2 is K, present in the composition in an amount within the range of about 0.05 wt. % to about 1 wt. %, calculated as K 2 O on a calcined basis.
10. The catalyst composition of claim 9 , further comprising M3, wherein M3 is selected from Mg, Ca, Sr, Ba, and Fe, present in an amount within the range of about 0.05 wt. % to about 7 wt. %, calculated as oxide on a calcined basis.
11. The catalyst composition of claim 9 , wherein M1 includes Ir.
12. The catalyst composition of claim 1 , wherein S1 is a mixture of alumina and silica, a mixture of alumina and zirconia, or a mixture of alumina and titania.
13. The catalyst composition of claim 1 , wherein
S1 is a mixture of alumina, silica, and zirconia;
alumina and silica are present in a weight ratio within the range of about 0.5:1 to about 25:1; and
alumina and zirconia are present in a weight ratio within the range of about 90:1 to about 40:1.
14. The catalyst composition of claim 1 , wherein S1 is present in the composition in an amount within the range of about 70 wt. % to about 99 wt. %.
15. The catalyst composition of claim 1 , wherein the composition comprises
none of or less than 1 wt. % of the lanthanides other than lanthanum and cerium; and
none of or less than 0.5 wt. % of chromium.
16. The catalyst composition of claim 1 , optionally including a promoter M1-B selected from Sn and Pd, and optionally including a promoter M3 selected from Mg, Ca, Sr, Ba, and Fe, wherein the total amount of gallium oxide, cerium oxide, M1, M1-B, M2, M3, and S1 is at least about 97.5 wt. % of the catalyst composition.
17. A method for preparing a dehydrogenation catalyst composition according to claim 1 , comprising
providing an aqueous solution comprising
a gallium source;
a cerium source;
an M1 source;
an M2 source; and
an S1 source;
forming a solid from the solution; and
calcining the solid so formed.
18. A method for dehydrogenating hydrocarbon, the method comprising contacting a hydrocarbon feed with the catalyst composition of claim 1 .
19. The catalyst composition of claim 1 , wherein S1 is a mixture of alumina and silica, present in a weight ratio of alumina to silica within the range of about 0.5:1 to about 25:1.
20. The catalyst composition of claim 1 , wherein S1 is a mixture of alumina and zirconia, present in a weight ratio of alumina to zirconia within the range of about 1:1 to about 25:1.