Chromium-catalyzed production of alcohols from hydrocarbons
Processes for converting a hydrocarbon reactant into an alcohol compound and/or a carbonyl compound are disclosed, and these processes include the steps of forming a supported chromium catalyst comprising chromium in a hexavalent oxidation state, irradiating the hydrocarbon reactant and the supported chromium catalyst with a light beam at a wavelength in the UV-visible spectrum to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst, and hydrolyzing the reduced chromium catalyst to form a reaction product comprising the alcohol compound and/or the carbonyl compound. The supported chromium catalyst can be formed by heat treating a supported chromium precursor, contacting a chromium precursor with a solid support while heat treating, or heat treating a solid support and then contacting a chromium precursor with the solid support.
1. A supported catalyst comprising:
a solid oxide comprising silica, silica-titania, silica-titania-magnesia, silica-coated alumina, or any combination thereof; and
an alkali metal chromate compound in an amount from about 0.1 to about 25 wt. % of chromium, based on the weight of the catalyst.
2. The catalyst of claim 1 , wherein the chromate compound comprises potassium chromate.
3. The catalyst of claim 1 , wherein the chromate compound comprises sodium chromate.
4. The catalyst of claim 1 , wherein the chromate compound comprises potassium dichromate.
5. The catalyst of claim 1 , wherein the chromate compound comprises sodium dichromate.
6. The catalyst of claim 1 , wherein the catalyst contains from about 0.25 to about 15 wt. % chromium.
7. The catalyst of claim 1 , wherein the catalyst further comprises from about 0.25 to about 15 wt. % alkali metal.
8. The catalyst of claim 1 , wherein the catalyst has:
a total pore volume from about 0.1 to about 3 mL/g; and
a BET surface area from about 50 to about 700 m 2 /g.
9. The catalyst of claim 1 , wherein the solid oxide comprises silica.
10. The catalyst of claim 9 , wherein the chromate compound comprises potassium chromate, sodium chromate, potassium dichromate, sodium dichromate, or any combination thereof.
11. The catalyst of claim 1 , wherein the catalyst contains from about 3 to about 15 wt. % chromium.
12. The catalyst of claim 1 , wherein the catalyst further comprises from about 3 to about 15 wt. % alkali metal.
13. The catalyst of claim 1 , wherein:
the solid oxide comprises silica; and
the catalyst has:
a total pore volume from about 0.1 to about 3 mL/g; and
a BET surface area from about 50 to about 700 m 2 /g.
14. The catalyst of claim 13 , wherein the chromate compound comprises potassium chromate, sodium chromate, potassium dichromate, sodium dichromate, or any combination thereof.
15. A supported catalyst comprising:
a solid oxide comprising silica-coated alumina; and
a chromate compound in an amount from about 0.1 to about 25 wt. % of chromium, based on the weight of the catalyst.
16. The catalyst of claim 15 , wherein the silica-coated alumina has a weight ratio of alumina to silica from about 1:5 to about 5:1.
17. The catalyst of claim 16 , wherein the chromate compound comprises potassium chromate, sodium chromate, ammonium chromate, potassium dichromate, sodium dichromate, ammonium dichromate, or any combination thereof.
18. The catalyst of claim 17 , wherein the weight ratio of alumina to silica is from about 1:3 to about 3:1.
19. The catalyst of claim 15 , wherein the catalyst contains from about 0.25 to about 15 wt. % chromium.
20. The catalyst of claim 19 , wherein the catalyst further comprises from about 0.25 to about 15 wt. % alkali metal.
21. The catalyst of claim 20 , wherein the catalyst has:
a total pore volume from about 0.1 to about 3 mL/g; and
a BET surface area from about 50 to about 700 m 2 /g.
22. The catalyst of claim 21 , wherein the weight ratio of alumina to silica is from about 1:1 to about 2:1.
23. The catalyst of claim 22 , wherein the chromate compound comprises potassium chromate, sodium chromate, potassium dichromate, sodium dichromate, or any combination thereof.