Chromium-catalyzed production of alcohols from hydrocarbons in the presence of oxygen
Processes for converting a hydrocarbon reactant into an alcohol compound and/or a carbonyl compound are disclosed in which the hydrocarbon reactant and either a supported chromium (VI) catalyst or a supported chromium (II) catalyst are contacted, optionally with UV-visible light irradiation, followed by exposure to an oxidizing atmosphere and then hydrolysis to form a reaction product containing the alcohol compound and/or the carbonyl compound. The presence of oxygen significant increases the amount of alcohol/carbonyl product formed, as well as the formation of oxygenated dimers and trimers of certain hydrocarbon reactants.
1. A process for converting a hydrocarbon reactant into an alcohol compound and/or a carbonyl compound, the process comprising:
(i) irradiating, in an oxidizing atmosphere, the hydrocarbon reactant and a supported chromium catalyst comprising chromium in a hexavalent oxidation state 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, or
(i) contacting, in an oxidizing atmosphere, the hydrocarbon reactant comprising an olefin and a supported chromium catalyst comprising chromium in a hexavalent oxidation state to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst; and
(ii) hydrolyzing the reduced chromium catalyst to form a reaction product comprising the alcohol compound and/or the carbonyl compound.
2. The process of claim 1 , wherein;
the light beam is from a blue light source or a UV light source;
the light beam comprises wavelengths above 350 nm and below 500 nm;
the hydrocarbon reactant and the supported chromium catalyst are irradiated with an illuminance of at least 10,000 lux; or
any combination thereof.
3. The process of claim 1 , wherein:
the supported chromium catalyst comprises a solid oxide, a chemically-treated solid oxide, a zeolite, or a combination thereof;
the supported chromium catalyst has a pore volume from 0.1 to 5 mL/g and a BET surface area from 50 to 2000 m 2 /g; and
step (i) is conducted at a temperature from −100° C. to 100° C.
4. The process of claim 1 , wherein the reaction product comprises an allylic alcohol.
5. The process of claim 1 , wherein the supported chromium catalyst contains from 0.01 to 50 wt. % chromium, based on the weight of the supported chromium catalyst.
6. The process of claim 1 , wherein:
the oxidizing atmosphere comprises air; and
a molar ratio of elemental oxygen in the oxidizing atmosphere to chromium of the supported chromium catalyst is at least 10:1.
7. The process of claim 1 , wherein a molar yield of the alcohol compound and/or the carbonyl compound is from 0.1 to 5 moles of the alcohol compound and/or the carbonyl compound per mole of chromium (VI) of the supported chromium catalyst.
8. A process for converting a hydrocarbon reactant into an alcohol compound and/or a carbonyl compound, the process comprising:
(I) irradiating the hydrocarbon reactant and a supported chromium catalyst comprising chromium in a hexavalent oxidation state 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, or
(I) contacting the hydrocarbon reactant comprising an olefin and a supported chromium catalyst comprising chromium in a hexavalent oxidation state to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst;
(II) subjecting the reduced chromium catalyst to an oxidizing atmosphere; and
(III) hydrolyzing the reduced chromium catalyst to form a reaction product comprising the alcohol compound and/or the carbonyl compound.
9. A process for converting a hydrocarbon reactant into an alcohol compound and/or a carbonyl compound, the process comprising:
(a) contacting the hydrocarbon reactant and a supported chromium (II) catalyst to form a treated chromium catalyst;
(b) subjecting the treated chromium catalyst to an oxidizing atmosphere; and
(c) hydrolyzing the treated chromium catalyst to form a reaction product comprising the alcohol compound and/or the carbonyl compound.
10. The process of claim 9 , wherein the hydrocarbon reactant comprises a C 1 to C 6 alkane compound.
11. The process of claim 9 , wherein the hydrocarbon reactant comprises an aromatic compound, a C 2 to C 12 olefin compound, or any combination thereof.
12. The process of claim 9 , wherein the reaction product comprises an allylic alcohol.
13. The process of claim 9 , wherein:
the supported chromium (II) catalyst comprises a solid oxide, a chemically-treated solid oxide, a zeolite, or a combination thereof;
the supported chromium (II) catalyst has a pore volume from 0.1 to 5 mL/g and a BET surface area from 50 to 2000 m 2 /g; and
step (a) and step (b) are conducted, independently, at a temperature from −100° C. to 100° C.
14. The process of claim 9 , wherein the supported chromium (II) catalyst contains from 0.01 to 50 wt. % chromium, based on the weight of the supported chromium (II) catalyst.
15. The process of claim 9 , wherein:
the oxidizing atmosphere comprises air;
a molar ratio of elemental oxygen in the oxidizing atmosphere to chromium of the supported chromium (II) catalyst is at least 10:1; and
a molar yield of the alcohol compound and/or the carbonyl compound is from 0.1 to 5 moles of the alcohol compound and/or the carbonyl compound per mole of chromium (II) of the supported chromium (II) catalyst.
16. The process of claim 8 , wherein
the light beam is from a blue light source or a UV light source;
the light beam comprises wavelengths above 350 nm and below 500 nm;
the hydrocarbon reactant and the supported chromium catalyst are irradiated with an illuminance of at least 10,000 lux; or
any combination thereof.
17. The process of claim 8 , wherein:
the supported chromium catalyst comprises a solid oxide, a chemically-treated solid oxide, a zeolite, or a combination thereof;
the supported chromium catalyst has a pore volume from 0.1 to 5 mL/g and a BET surface area from 50 to 2000 m 2 /g; and
step (I) is conducted at a temperature from −100° C. to 100° C.
18. The process of claim 8 , wherein the reaction product comprises an allylic alcohol.
19. The process of claim 8 , wherein the supported chromium catalyst contains from 0.01 to 50 wt. % chromium, based on the weight of the supported chromium catalyst.
20. The process of claim 8 , wherein:
the oxidizing atmosphere comprises air; and
a molar ratio of elemental oxygen in the oxidizing atmosphere to chromium of the supported chromium catalyst is at least 10:1.