Surface-modified electrodes and their use in CO2 and CO reduction

Patent metadata

Field	Value
Publication number	US-12203180-B2
Application number	US-202017422328-A
Country	US
Kind code	B2
Filing date	Jan 29, 2020
Priority date	Jan 29, 2019
Publication date	Jan 21, 2025
Grant date	Jan 21, 2025

Abstract

Disclosed are surface modified electrodes, their process of preparation and their use in the electrolytic reduction of carbon dioxide and/or carbon monoxide, as well as an electrochemical cell including the electrode.

First claim

The invention claimed is:

1. An electrode comprising:
a metallic nanostructure, the metal of which is selected from the group of Cu, Zn, Ni, Fe, and Ag or mixtures thereof, said metallic nanostructure being part of a metallic hierarchical structure containing both micro and nanostructuration, said metallic hierarchical structure being of the same metal as defined above,
a hydrophobic layer of compounds covering the surface of said metallic hierarchical structure, said compounds being chemisorbed to said surface,
said metallic hierarchical structure being porous,
said compounds being chosen from the group of:
a compound of Formula 1,
R—A  Formula 1

wherein,
A represents,
SH,
—P(O)(OH)2,
—CO2H,
—SeH,
—TeH,
—Si(OH)3,
Six3, wherein X represents a halogen,
an acetylacetone group having the structure of Formula 2,

R is chosen from the groups of,
(C5-C100)-alkyl linear or branched,
(C5-C100)-alkenyl linear or branched,
(C5-C100)-alkynyl linear or branched,
(C5-C100)-heteroralkyl linear or branched,
(C5-C100)-heteroalkenyl linear or branched,
(C5-C100)-heteroalkynyl linear or branched,
said alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl and heteroalkynyl can be further substituted by one or more groups selected from:
amines,
—ORa, wherein Ra represents a hydrogen atom, a (C1-C20)-alkyl group, a (C1-C10)-alkyl group, or a (C1-C5)-alkyl group,
halogen,
aryl,
—CO2Rb, wherein Rb represents a hydrogen atom, a (C1-C20)-alkyl group, a (C1-C10)-alkyl group, or a (C1-C5)-alkyl group,
—CX3 groups, wherein X represents a halogen,
a compound of Formula 3,

wherein,
A represents Se or S,
R is a group as defined above,
polysiloxane compounds chosen from the groups of (C1-C100)-polyalkylsiloxane, or polyarylsiloxane, said polyalkylsiloxane and polyarylsiloxane can be further substituted by one or more groups selected from:
amines,
—ORa, wherein Ra represents a hydrogen atom, a (C1-C20)-alkyl group, a (C1-C10)-alkyl group, or a (C1-C5)-alkyl group,
halogen, wherein X represents a halogen,
—CO2Ra, wherein Ra represents a hydrogen atom, a (C1-C20)-alkyl group, a (C1-C10)-alkyl group, or a (C1-C5)-alkyl group,
said electrode having a hydrophobicity as determined by contact angle measurement from 130° to 175°,
said electrode having an electrochemically active surface area (EASA) lower than 10% of the geometric surface area of said metallic hierarchical structure,
wherein regions of the electrochemically active surface area are located at extremities of said metallic hierarchical structure, and
wherein the electrochemically active surface area is exposed to an electrolyte solution.

2. The electrode according to claim 1 , wherein said metal is chosen from Cu or Zn, or mixtures of Cu and Ag or mixtures of Zn and Ag.

3. The electrode according to claim 1 , wherein said compound is chosen from a compound of Formula 1, wherein A represents-SH.

4. The electrode according to claim 3 , wherein said compound is 1-octadecanethiol or 1-dodecanethiol.

5. The electrode according to claim 1 ,
wherein said metal is chosen from Cu, and
wherein said compound is chosen from a compound of Formula 1, wherein A represents-SH, and
wherein said metallic hierarchical structure is dendritic.

6. The electrode according to claim 1 , wherein said metallic nanostructure contains dendritic hierarchical structures.

7. The electrode according to claim 1 , wherein the hydrophobic layer is structurally and chemically stable during electrolysis at currents in the range of −0.1 to −50 mA cm −2 and at potentials in the range of −1.5 V to −4 V.

8. The electrode according to claim 1 , wherein gas bubbles are trapped between the surface of the metallic hierarchical structure and the electrolyte solution.

9. A method for the implementation of an electrochemical reaction, said electrochemical reaction being the reduction of CO2 or CO gas or mixture thereof into hydrocarbon(s) or alcohol(s) or mixtures thereof in aqueous medium, or the reduction of CO2 gas into CO in aqueous medium, wherein the method comprises a step of contacting said CO2 gas, or said CO gas, with an electrode comprising or consisting of:
a metallic nanostructure, the metal of which is selected from the group of Cu, Zn, Ni, Fe, and Ag or mixtures thereof, said metallic nanostructure being part of a metallic hierarchical structure containing both micro and nanostructuration, said metallic hierarchical structure being of the same metal as defined above,
a hydrophobic layer of compounds covering the surface of said metallic hierarchical structure, said compounds being chemisorbed to said surface,
said metallic hierarchical structure being porous,
said compounds being chosen from the group of:
a compound of Formula 1,
R—A  Formula 1

wherein,
A represents,
—SH,
—P(O)(OH)2,
—CO2H,
—SeH,
—TeH,
—Si(OH)3,
Six3, wherein X represents a halogen,
an acetylacetone group having the structure of Formula 2,

R is chosen from the groups of,
(C5-C100)-alkyl linear or branched,
(C5-C100)-alkenyl linear or branched,
(C5-C100)-alkynyl linear or branched,
(C5-C100)-heteroralkyl linear or branched,
(C5-C100)-heteroalkenyl linear or branched,
(C5-C100)-heteroalkynyl linear or branched,
said alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl and heteroalkynyl can be further substituted by one or more groups selected from:
amines,
—ORa, wherein Ra represents a hydrogen atom, a (C1-C20)-alkyl group, a (C1-C10)-alkyl group, or a (C1-C5)-alkyl group,
halogen,
aryl,
—CO2Rb, wherein Rb represents a hydrogen atom, a (C1-C20)-alkyl group, a (C1-C10)-alkyl group, or a (C1-C5)-alkyl group,
—CX3 groups, wherein X represents a halogen,
a compound of Formula 3,

wherein,
A represents Se or S,
R is a group as defined above,
polysiloxane compounds chosen from the groups of (C1-C100)-polyalkylsiloxane, or polyarylsiloxane, said polyalkylsiloxane and polyarylsiloxane can be further substituted by one or more groups selected from:
amines,
—ORa, wherein Ra represents a hydrogen atom, a (C1-C20)-alkyl group, a (C1-C10)-alkyl group, or a (C1-C5)-alkyl group,
halogen, wherein X represents a halogen,
—CO2Ra, wherein Ra represents a hydrogen atom, a (C1-C20)-alkyl group, a (C1-C10)-alkyl group, or a (C1-C5)-alkyl group,
said electrode having a hydrophobicity as determined by contact angle measurement from 130° to 175°,
said electrode having an electrochemically active surface area (EASA) lower than 10% of the geometric surface area of said metallic hierarchical structure,
wherein regions of the electrochemically active surface area are located at extremities of said metallic hierarchical structure, and
wherein the electrochemically active surface area is exposed to an electrolyte solution.

10. The method according to claim 9 , for the reduction of CO 2 or CO gas or mixture thereo

Assignees

• Paris Sciences Et Lettres
• College France
• Centre Nat Rech Scient
• Centre National De La Rechereche Scient

Inventors

• Fontecave Marc
• Mougel Victor
• Wakerley David
• Lamaison Sarah

Classifications

• C25B11/042

  Electrodes formed of a single material · CPC title

• C25B3/26

  of carbon dioxide · CPC title

• C25B3/03

  Acyclic or carbocyclic hydrocarbons · CPC title

• C25B3/07

  Oxygen containing compounds · CPC title

• C25B1/23

  Carbon monoxide or syngas · CPC title