Photochemical composition and use thereof for producing CH4 from CO2 and/or CO

Patent metadata

Field	Value
Publication number	US-10960388-B2
Application number	US-201815879650-A
Country	US
Kind code	B2
Filing date	Jan 25, 2018
Priority date	Jan 25, 2018
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

Abstract

The present invention relates to photochemical compositions comprising:
a solution comprising an organic solvent, preferably selected from dimethylformamide, acetonitrile, and mixtures thereof with water, a sacrificial electron donor; a proton donor having a pKa in acetonitrile greater than or equal to 28; a photosensitizer whose reduced state has a standard redox potential more negative than −1.45 V vs SCE; and a metal porphyrin complex of formula (I) as defined in claim 1,

useful in the production of CH 4 from CO 2 or CO by photochemical catalysis, to a photochemical cell comprising same and to a method for producing CH 4 from CO 2 or CO by photochemical catalysis using same.

First claim

The invention claimed is:

1. A photochemical composition for producing methane by reducing at least one of CO 2 and CO at visible light, comprising:
a solution comprising an organic solvent,
a sacrificial electron donor;
a proton donor having a pKa in acetonitrile greater than or equal to 28;
a photosensitizer whose reduced state has a standard redox potential more negative than −1.45 V vs Saturated Calomel Electrode, wherein the photosensitizer is a complex of a transition metal with at least two 2-phenylpyridine (ppy) ligand; and
a metal porphyrin complex of formula (I):

wherein:
M represents a transition metal ion,
R 1 to R 10 and R 1 ′ to R 10 ′ are independently selected from the group consisting of H, OH, F, C 1 -C 6 alcohol, and N + (C 1 -C 4 alkyl) 3 ,
and wherein:
at least one of R 1 to R 5 is OH and at least one of R 1′ to R 5′ is OH, or
at least one of R 1 to R 5 is N + (C 1 -C 4 alkyl) 3 , and at least one of R 1′ to R 5′ is N + (C 1 -C 4 alkyl) 3 ,
and salts thereof.

2. The photochemical composition of claim 1 , wherein the photosensitizer having a standard redox potential more negative than −1.35 V vs Saturated Calomel Electrode in the reduced state is a metal complex of formula (III):

wherein Y 1 , Y 2 and Y 3 are CH 2 , and M′ represents a transition metal.

3. The photochemical composition of claim 1 , wherein the concentration of photosensitizer in the photochemical composition is of between 50 mM and 1 mM.

4. The photochemical composition of claim 1 , wherein the concentration of sacrificial electron donor in the photochemical composition is of between 10 mM and 500 mM.

5. The photochemical composition of claim 1 , wherein the sacrificial electron donor is a tertiary amine.

6. The photochemical composition of claim 5 , wherein the tertiary amine is:
of formula NR 1 R 2 R 3 , in which R 1 , R 2 and R 3 are identical or different and each independently selected from a C 1 -C 6 alkyl group optionally substituted with OH, OC 1 -C 6 alkyl, or COOH; or
of formula (IV):

wherein
X′ is O or NR, with R representing a (C 1 -C 4 )alkyl,
R′ is a (C 1 -C 4 ) alkyl,
R″ is a hydrogen, halogen, CN, or a (C 1 -C 4 ) alkyl, and
Ar 4 is selected from a monocyclic or bicyclic 5- to 10-membered aromatic or heteroaromatic ring, optionally substituted by a halogen, CN, OH, a biaryl group or a monocyclic 5- or 6-membered aromatic or heteroaromatic ring, said monocyclic 5- or 6-membered aromatic or heteroaromatic ring being optionally substituted by a halogen, CN, OH.

7. The photochemical composition of claim 1 , wherein the proton donor is phenol or trifluoroethanol.

8. The photochemical composition of claim 1 , wherein the metal porphyrin complex of formula (I) comprises at least two N + (C 1 -C 4 alkyl) 3 groups.

9. The photochemical composition of claim 1 , wherein, in the metal porphyrin complex of formula (I):
at least one of R 6 to R 10 is OH and at least one of R 6′ to R 10′ is OH, or
at least one of R 6 to R 10 is N + (C 1 -C 4 alkyl) 3 , and at least one of R 6′ to R 10′ is N + (C 1 -C 4 alkyl) 3 .

10. The photochemical composition of claim 1 , wherein in the metal porphyrin complex of formula (I):
R 1 to R 10 and R 1′ to R 10′ are independently H or N + (C 1 -C 4 alkyl) 3 ,
at least one and at most two of R 1 to R 5 represent N + (C 1 -C 4 alkyl) 3 , and
at least one and at most two of R 1′ to R 5′ represent N + (C 1 -C 4 alkyl) 3 .

11. The photochemical composition of claim 1 , wherein the metal porphyrin complex of formula (I) is selected from:

and salts thereof.

12. The photochemical composition of claim 1 , wherein:
the sacrificial electron donor is the tertiary amine of formula NR 1 R 2 R 3 , in which R 1 , R 2 and R 3 are identical or different and each independently selected from a C 1 -C 6 alkyl group optionally substituted with OH, OC 1 -C 6 alkyl, or COOH;
the photosensitizer is the following complex:

the metal porphyrin complex is

the solvent is acetonitrile;
phenol or trifluoroethanol as a proton donor.

13. The photochemical composition of claim 1 , wherein the concentration of the metal porphyrin complex of formula (I) as defined in claim 1 is between 1 mM and 50 mM.

14. A method for producing methane from CO 2 or CO, said method comprising:
a) contacting gaseous CO 2 or CO, with a photochemical composition as claimed in claim 1 to obtain a solution comprising dissolved at least one of CO 2 and CO;
b) irradiation of said solution with visible light; and
c) collecting methane.

15. The method of claim 14 , wherein the pressure of CO 2 or CO of less than 1 bar.

16. The method of claim 14 , wherein the pressure of CO 2 or CO is of 1 bar or more.

17. The method of claim 14 , wherein:
the concentration of a sacrificial electron donor is between 10 mM and 500 mM,
the concentration of the photosensitizer is between 50 mM and 1 mM,
the concentration of the metal porphyrin complex of formula (I) is between 1 mM and 50 mM, the concentration of a proton donor is between 1 mM and 1 M.

18. The method of claim 14 , wherein the irradiation lasts several days with wavelength λ of 400 nm or more, the reaction being stable.

Assignees

• Univ Paris Diderot Paris 7
• Centre Nat Rech Scient

Inventors

• Robert Marc
• Bonin Julien

Classifications

• C07D487/22 Primary

  in which the condensed system contains four or more hetero rings · CPC title

• C07C1/10

  from carbon monoxide with water vapour · CPC title

• G01N30/7206

  interfaced to gas chromatograph (interfaces in general for introducing or extracting samples to be analysed with specially adapted mass spectrometer, see H01J49/04) · CPC title

• B01J31/183 Primary

  with more than one complexing nitrogen atom, e.g. phenanthroline · CPC title

• C07C2531/18

  containing nitrogen, phosphorus, arsenic or antimony · CPC title