Photocatalytic carbon dioxide reduction method using a photocatalyst in the form of a porous monolith

Patent metadata

Field	Value
Publication number	US-2021106977-A1
Application number	US-201816608568-A
Country	US
Kind code	A1
Filing date	Apr 23, 2018
Priority date	Apr 28, 2017
Publication date	Apr 15, 2021
Grant date	—

Abstract

The invention relates to a photocatalytic carbon dioxide reduction method carried out in liquid and/or gas phase under irradiation, using a photocatalyst containing a first semiconductor, particles comprising one or more metallic-state elements M, and a second semiconductor SC, wherein the method is carried out by contacting a feedstock containing the CO 2 and at least one sacrificial compound with the photocatalyst, then irradiating the photocatalyst such that the CO 2 is reduced, and oxidising the sacrificial compound in order to produce an effluent containing at least in part C1 or above carbon molecules other than CO 2 .

First claim

1 . A photocatalytic carbon dioxide reduction process carried out in the liquid phase and/or in the gas phase under irradiation using a photocatalyst in the form of a porous monolith containing at least one semiconductor, which process comprises the following steps:
a) a feedstock containing carbon dioxide and at least one sacrificial compound is brought into contact with a photocatalyst which is in the form of a porous monolith comprising a bulk density of less than or equal to 0.25 g/ml; b) the photocatalyst is irradiated with at least one irradiation source producing at least one wavelength lower than the bandgap of said photocatalyst, said step b) being carried out at a temperature of between −10° C. and 200° C., and at a pressure of between 0.01 MPa and 70 MPa.

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

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

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

5 . The process as claimed in claim 1 , wherein the photocatalyst in the form of a porous monolith has a mesoporous volume, of which the pore diameter is greater than 0.2 nm and less than or equal to 50 nm, of between 0.01 and 1 ml/g.

6 . The process as claimed in claim 1 , wherein the photocatalyst in the form of a porous monolith has a type-I macroporous volume, of which the pore diameter is greater than 50 nm and less than or equal to 1000 nm, of between 0.1 and 3 ml/g.

7 . The process as claimed in claim 1 , wherein the photocatalyst in the form of a porous monolith has a type-II macroporous volume, of which the pore diameter is greater than 1 μm and less than or equal to 10 μm, of between 0.1 and 8 ml/g.

8 . The process as claimed in claim 1 , wherein the photocatalyst in the form of a porous monolith comprises a mesoporosity and/or a type-I macroporosity and/or a type-II macroporosity.

9 . The process as claimed in claim 1 , wherein the photocatalyst in the form of a porous monolith comprises a macroporous volume, of which the pore diameter is greater than 10 μm, of less than 0.5 ml/g.

10 . The process as claimed in claim 1 , wherein the photocatalyst in the form of a porous monolith comprises a bulk density of less than 0.19 g/ml.

11 . The process as claimed in claim 1 , wherein the photocatalyst in the form of a porous monolith has a specific surface area of between 10 and 1000 m 2 /g.

12 . The process as claimed in claim 1 , wherein the photocatalyst in the form of a porous monolith comprises at least one semiconductor and at least one inorganic phase containing silica or alumina not absorbing photons with an energy greater than 4 eV.

13 . The process as claimed in claim 1 , in which the semiconductor content is between 5% and 70% by weight relative to the total weight of the photocatalyst.

14 . The process as claimed in claim 1 , wherein the photocatalyst in the form of a porous monolith consists of said semiconductor in monolith form.

15 . The process as claimed in claim 1 , wherein the semiconductor is chosen from TiO 2 , ZnO, Cu 2 O, CuO, Ce 2 O 3 , CeO 2 , In 2 O 3 , SiC, ZnS and In 2 S 3 , alone or as a mixture.

Assignees

• Ifp Energies Now

Inventors

• Bernadet Sophie
• Fecant Antoine
• Uzio Denis
• Backov Renal-Vasco
• Ravaine Serge

Classifications

• B01J35/32

  Bulk density · CPC title

• B01J2235/00

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

• B01J35/56

  Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional [3D] monoliths · CPC title

• B01D2259/804

  UV light · CPC title

• B01D2255/9207

  Specific surface · CPC title