Method for the photocatalytic reduction of carbon dioxide implementing a supported photocatalyst made from molybdenum sulfide or tungsten sulfide

Patent metadata

Field	Value
Publication number	US-11724253-B2
Application number	US-201816764131-A
Country	US
Kind code	B2
Filing date	Nov 7, 2018
Priority date	Nov 15, 2017
Publication date	Aug 15, 2023
Grant date	Aug 15, 2023

Abstract

The invention concerns a method for the photocatalytic reduction of carbon dioxide carried out in the liquid phase and/or in the gas phase under irradiation using a photocatalyst comprising a support made from alumina or silica or silica-alumina and nanoparticles of molybdenum sulfide or tungsten sulfide having a band gap greater than 2.3 eV, said method comprising the following steps: a) bringing a feedstock containing carbon dioxide and at least one sacrificial compound into contact with said photocatalyst, b) irradiating the photocatalyst with at least one source of irradiation producing at least one wavelength smaller than the width of the band gap of said photocatalyst so as to reduce the carbon dioxide and oxidise the sacrificial compound in the presence of said photocatalyst activated by said source of irradiation, in such a way as to produce an effluent containing, at least in part, C1 or above carbon-containing molecules, different from CO2.

First claim

The invention claimed is:

1. A process for photocatalytic reduction of carbon dioxide carried out in the liquid phase and/or in the gas phase under irradiation using a photocatalyst comprising a support based on alumina or silica or silica-alumina and nanoparticles of molybdenum sulfide or of tungsten sulfide having a bandgap greater than 2.3 eV, said process comprising the following steps:
a) bringing a feedstock containing carbon dioxide and at least one sacrificial compound into contact with said photocatalyst,
b) irradiating the photocatalyst with at least one irradiation source producing at least one wavelength smaller than the bandgap of said photocatalyst so as to reduce the carbon dioxide and to oxidize the sacrificial compound in the presence of said photocatalyst activated by said irradiation source, in such a way as to produce an effluent containing, at least partly, C1 or above carbon-based molecules other than CO 2 ,
wherein the content of molybdenum sulfide or of tungsten sulfide of the photocatalyst is between 4 and 50% by weight relative to the total weight of the photocatalyst.

2. The process as claimed in claim 1 , wherein, when it is carried out in the gas phase, the sacrificial compound is a gaseous compound selected from water, ammonia, hydrogen, methane and an alcohol.

3. The process as claimed in claim 1 , wherein, when it is carried out in the liquid phase, the sacrificial compound is a liquid compound selected from water, aqueous ammonia, an alcohol, an aldehyde and an amine.

4. The process as claimed in claim 1 , wherein a diluent fluid is present in steps a) and/or b).

5. The process as claimed in claim 1 , wherein the irradiation source is an artificial or natural irradiation source.

6. The process as claimed in claim 1 , wherein the irradiation source emits at at least one wavelength range greater than 280 nm.

7. The process as claimed in claim 1 , wherein the porous support does not absorb photons of energy greater than 4 eV.

8. The process as claimed in claim 1 , wherein the content of molybdenum sulfide or of tungsten sulfide of the photocatalyst is between 5 and 25% by weight relative to the total weight of the photocatalyst.

9. The process as claimed in claim 1 , wherein the surface density which corresponds to the amount of molybdenum Mo atoms or of tungsten W atoms, deposited per unit surface area of support, is between 0.5 and 12 atoms of Mo or W per square nanometer of support.

10. The process as claimed in claim 1 , wherein the photocatalyst is prepared according to a process comprising the following successive steps:
i) a step of impregnation by bringing a solution comprising an organic solvent A and at least one mononuclear precursor based on Mo or on W, denoted M, in their monomeric or dimeric form, having at least one M═O or M—OR bond or at least one M═S or M—SR bond where R═C x H y where x≥1 and (x−1)≤y≤(2x+1), into contact with a support based on alumina or silica or silica-alumina, advantageously previously calcined under vacuum or under an inert gas stream to remove the water possibly physisorbed on said support,
ii) a maturing step,
iii) a step of drying the impregnated support, at a temperature below 200° C., under an anhydrous atmosphere or under vacuum or under an inert gas stream,
iv) a sulfurization step.

11. The process as claimed in claim 10 , wherein the molybdenum precursor is selected from the following compounds: Mo(OEt) 5 , Mo(OEt) 6 , Mo(═O)(OEt) 4 , Mo(═S)(OEt) 4 , Mo(═S)(SEt) 4 , Mo(═O) 2 (OEt) 2 , Mo(OC 6 H 5 ) 6 , Mo(SEt) 5 , Mo(SEt) 6 , Mo(OEt)(SEt) 4 , Mo(OEt) 2 (SEt) 3 , Mo(OEt) 3 (SEt) 2 , Mo(OEt) 4 (SEt), Mo(═O)(OEt) 3 (acac) with Et=CH 2 CH 3 (ethyl group) and acac=(CH 3 COCHCOCH 3 )— (acetylacetonate) in their monomeric or dimeric form.

12. The process as claimed in claim 10 , wherein the tungsten precursor is selected from the following compounds: W(OEt) 5 , W(OEt) 6 , W(═O)(OEt) 4 , W(═S)(OEt) 4 , W(═S)(SEt) 4 , W(═O) 2 (OEt) 2 , W(OC 6 H 5 ) 6 , W(SEt) 5 , W(SEt) 6 , W(OEt) 4 (SEt), W(OEt) 3 (SEt) 2 , W(OEt) 2 (SEt) 3 , W(OEt)(SEt) 4 , W(═O)(OEt) 3 (acac) with Et=CH 2 CH 3 (ethyl group) and acac=(CH 3 COCHCOCH 3 )— (acetylacetonate), in their monomeric or dimeric form.

13. A process for photocatalytic reduction of carbon dioxide carried out in the liquid phase and/or in the gas phase under irradiation using a photocatalyst comprising a support based on alumina or silica or silica-alumina and nanoparticles of molybdenum sulfide or of tungsten sulfide having a bandgap greater than 2.3 eV, said process comprising the following steps:
a) bringing a feedstock containing carbon dioxide and at least one sacrificial compound into contact with said photocatalyst,
b) irradiating the photocatalyst with at least one irradiation source producing at least one wavelength smaller than the bandgap of said photocatalyst so as to reduce the carbon dioxide and to oxidize the sacrificial compound in the presence of said photocatalyst activated by said irradiation source, in such a way as to produce an effluent containing, at least partly, C1 or above carbon-based molecules other than CO 2 ,

wherein
the photocatalyst is prepared according to a process comprising the following successive steps:
i) a step of impregnation by bringing a solution comprising an organic solvent A and at least one mononuclear precursor based on Mo or on W, denoted M, in their monomeric or dimeric form, having at least one M═O or M—OR bond or at least one M═S or M—SR bond where R═C x H y where x≥1 and (x−1)≤y≤(2x+1), into contact with a support based on alumina or silica or silica-alumina, advantageously previously calcined under vacuum or under an inert gas stream to remove the water possibly physisorbed on said support,
ii) a maturing step,
iii) a step of drying the impregnated support, at a temperature below 200° C., under an anhydrous atmosphere or under vacuum or under an inert gas stream,
iv) a sulfurization step.

14. A process for photocatalytic reduction of carbon dioxide carried out in the liquid phase and/or in the gas phase under irradiation using a photocatalyst comprising a support based on alumina or silica or silica-alumina and nanoparticles of molybdenum sulfide or of tungsten sulfide having a bandgap greater than 2.3 eV, said process comprising the following steps:
a) bringing a feedstock containing carbon dioxide and at least one sacrificial compound into contact with said photocatalyst,
b) irradiating the photocatalyst with at least one irradiation source producing at least one wavelength smaller than the bandgap of said photocatalyst so as to reduce the carbon dioxide and to oxidize the sacrificial compound in the presence of said photocatalyst activated by said irradiation source, in such a way as to produce an effluent containing, at least partly, C1 or above carbon-based molecules other than CO 2 ,

wherein
the surface density which corresponds to the amount of molybdenum Mo atoms or of tungsten W atoms, deposited per unit surface area of support, is between 0.5 and 12 atoms of Mo or W per square nanometer of support;
or
the molybdenum precursor is selected from the following compounds: Mo(OEt) 5 , Mo(OEt) 6 , Mo(═O)(OEt) 4 , Mo(═S)(OEt) 4 , Mo(═S)(SEt) 4 , Mo(═O) 2 (OEt) 2 , Mo(OC 6 H 5 ) 6 , Mo(SEt) 5 , Mo(SEt) 6 , Mo(OEt)(SEt) 4 , Mo(OEt) 2 (SEt) 3 , Mo(OEt) 3 (SEt) 2 , Mo(OEt) 4 (SEt), Mo(═O)(OEt) 3 (acac) with Et=CH 2 CH 3 (ethyl group) and acac=(CH 3 COCHCOCH 3 )— (acetylacetonate) in their monomeric or dimeric form;
or
the tungsten precursor is selected from the following compounds: W(OEt) 5 , W(OEt) 6 , W(═O)(O

Assignees

• Ifp Energies Now

Inventors

• Fecant Antoine
• Bonduelle-Skrzypczak Audrey
• Atwi Ranin

Classifications

• B01J2235/00

  Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties · CPC title

• B01J35/39 Primary

  Photocatalytic properties · CPC title

• B01J35/19

  Catalysts containing parts with different compositions · CPC title

• B01J35/33

  Electric or magnetic properties · CPC title

• B01J37/345 Primary

  of ultraviolet wave energy · CPC title