Method for Converting Carbon Dioxide (CO2) into CO by an Electrolysis Reaction

Patent metadata

Field	Value
Publication number	US-2022056602-A1
Application number	US-201917415102-A
Country	US
Kind code	A1
Filing date	Dec 19, 2019
Priority date	Dec 19, 2018
Publication date	Feb 24, 2022
Grant date	—

Abstract

The present invention relates to an electrode comprising a metal deposit of zinc and silver, a process for preparing such an electrode, an electrolysis device comprising such an electrode and a method for CO 2 electroreduction to CO using such an electrode as a cathode.

First claim

1 . An electrode comprising an electrically conductive support of which at least a part of the surface is covered by a metal deposit of zinc and silver, wherein said metal deposit has a specific surface area greater than or equal to 0.1 m 2 ·g −1 .

2 . The electrode according to claim 1 , wherein the electrically conductive support comprises an electrically conductive material selected from the group consisting of a metal; a metal oxide; a metal sulfide; carbon; a polymer intrinsically electrically conductive or made conductive by a coating with a film of conductive material; a semiconductor; and a mixture thereof;
and optionally wherein the electrode has been submitted to a treatment to modify its conductivity; a treatment to modify its hydrophobicity, or a combination thereof.

3 . The electrode according to claim 1 , wherein the metal deposit has a specific surface area between 0.1 and 500 m 2 ·g −1 .

4 . The electrode according to claim 1 , wherein the metal deposit comprises at least 1 wt % of one or several phases of an alloy of zinc and silver.

5 . The electrode according to claim 1 , wherein the metal deposit has a thickness comprised between 1 μm and 500 μm.

6 . The electrode according to claim 1 , wherein the metal deposit has a porous structure with an average pore size of between 1 μm and 500 μm.

7 . A process for preparing an electrode according to claim 1 comprising the following successive steps:
(i) providing an electrically conductive support;
(ii) immersing said electrically conductive support at least partially in an acidic aqueous solution containing ions of zinc and ions of silver; and
(iii) applying a current or a potential between the electrically conductive support and a second electrode in order to form a metal deposit of zinc and silver on the electrically conductive support, so as to have a current density equal to or less than −0.1 A·cm −2 between the electrically conductive support and a second electrode.

8 . The process according to claim 7 , wherein the acidic aqueous solution containing ions of zinc and ions of silver is an acidic aqueous solution containing:
a salt of zinc; an oxidised zinc species; a Zn(OH) 3− -based salt; a Zn(OH) 4 2− -based salt; a ZnO 2 2− -based salt; or a mixture thereof;
a salt of silver; an oxidised species of silver; or a mixture thereof.

9 . The process according to claim 7 , wherein the metal deposit of zinc and silver is removed from the electrically conductive support and applied on a second electrically conductive support.

10 . An electrolysis device comprising an electrode according to claim 1 .

11 . The electrolysis device according to claim 10 , coupled to a source of an electrical energy.

12 . A method for converting carbon dioxide (CO 2 ) into CO comprising the following steps:
a) providing an electrolysis device comprising an anode and a cathode, wherein said cathode is an electrode according to claim 1 ; b) exposing the cathode of said electrolysis device to a gaseous or liquid CO 2 -containing composition; c) applying an electrical current or a potential between the anode and the cathode in order to reduce the carbon dioxide into CO.

13 . The method according to claim 12 , being performed under a CO 2 pressure of from 100 to 100000 kPa.

14 . The method according to claim 12 , being performed at a temperature from 10 to 100° C.

15 . The method according to claim 12 , wherein the gaseous or liquid CO 2 -containing composition is a CO 2 -containing aqueous catholyte solution or a gaseous CO 2 -containing composition.

16 . The electrode according to claim 2 , wherein the carbon is in the form of carbon felt, graphite, vitreous carbon, carbon nanofibers, carbon nanotubes, carbon black, boron-doped diamond, any form of gas diffusion layer (GDL) with or without microporous layer.

17 . The electrode according to claim 2 , wherein the metal deposit has a specific surface area between 1 and 25 m 2 ·g −1 .

18 . The electrode according to claim 4 , wherein the one or several phases of an alloy of zinc and silver is a phase Ag 0.13 Zn 0.87 .

19 . The process according to claim 7 , wherein the current density between the electrically conductive support and the second electrode is between −5 A·cm −2 and −0.1 A·cm −2 .

20 . The method according to claim 12 , being performed under a CO 2 pressure of from 100 to 1000 kPa.

Assignees

• Paris Sciences Et Lettres
• College France

Inventors

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

Classifications

• Y02E60/50

  Fuel cells · CPC title

• C25C1/24

  Alloys obtained by cathodic reduction of all their ions · CPC title

• C25D1/08

  Perforated or foraminous objects, e.g. sieves (C25D1/10 takes precedence) · CPC title

• C25B3/26

  of carbon dioxide · CPC title

• C25B11/089

  Alloys · CPC title