CO2 reduction toward methane

Patent metadata

Field	Value
Publication number	US-11512399-B2
Application number	US-202017116220-A
Country	US
Kind code	B2
Filing date	Dec 9, 2020
Priority date	Dec 9, 2019
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

An electrode of a chemical cell includes a substrate having a surface, an array of conductive projections supported by the substrate and extending outward from the surface of the substrate, each conductive projection of the array of conductive projections having a semiconductor composition for reduction of carbon dioxide (CO 2 ) in the chemical cell, and a catalyst arrangement disposed along each conductive projection of the array of conductive projections, the catalyst arrangement including a copper-based catalyst and an iron-based catalyst for the reduction of carbon dioxide (CO 2 ) in the chemical cell.

First claim

What is claimed is:

1. An electrode of a chemical cell, the electrode comprising:
a substrate having a surface;
an array of conductive projections supported by the substrate and extending outward from the surface of the substrate, each conductive projection of the array of conductive projections having a semiconductor composition for reduction of carbon dioxide (CO2) in the chemical cell; and
a catalyst arrangement disposed along each conductive projection of the array of conductive projections, the catalyst arrangement comprising a copper-based catalyst and an iron-based catalyst for the reduction of carbon dioxide (CO2) in the chemical cell.

2. The electrode of claim 1 , wherein the copper-based catalyst comprises a plurality of copper nanoparticles.

3. The electrode of claim 1 , wherein the iron-based catalyst comprises a distribution of iron oxide disposed in a co-catalyst arrangement with the copper-based catalyst.

4. The electrode of claim 1 , wherein the copper-based catalyst is disposed between the iron-based catalyst and the conductive projection.

5. The electrode of claim 1 , wherein the copper-based catalyst and the iron-based catalyst are linked by a metallic bond.

6. The electrode of claim 1 , wherein:
the substrate comprises a semiconductor material; and
the semiconductor material is configured to generate charge carriers upon absorption of solar radiation such that the chemical cell is configured as a photoelectrochemical system.

7. The electrode of claim 6 , wherein the array of conductive projections are configured to extract the charge carriers generated in the substrate.

8. The electrode of claim 1 , wherein each conductive projection of the array of conductive projections comprises a respective nanowire.

9. The electrode of claim 1 , wherein each conductive projection of the array of conductive projections comprises a Group III-V semiconductor material.

10. The electrode of claim 1 , wherein the substrate is planar.

11. The electrode of claim 1 , wherein the semiconductor composition of the array of conductive projections establishes a Schottky junction with the catalyst arrangement.

12. The electrode of claim 1 , wherein the catalyst arrangement has an iron-to-copper ratio of about 6.3 to 1.

13. The electrode of claim 1 , wherein the copper-based catalyst may be partially oxidized.

14. The electrode of claim 1 , wherein the chemical cell is a thermochemical cell.

15. An electrochemical system comprising a working electrode configured in accordance with the electrode of claim 1 , and further comprising:
a counter electrode;
an electrolyte in which the working and counter electrodes are immersed; and
a voltage source that applies a bias voltage between the working and counter electrodes;
wherein the bias voltage establishes a preference for the reduction of carbon dioxide (CO2) at the working electrode toward methane.

16. A photocathode for a photoelectrochemical cell, the photocathode comprising:
a substrate comprising a light absorbing material, the light absorbing material being configured to generate charge carriers upon solar illumination;
an array of conductive projections supported by the substrate, each conductive projection of the array of conductive projections being configured to extract the charge carriers from the substrate;
a plurality of catalyst particles disposed across each conductive projection of the array of conductive projections, each catalyst particle of the plurality of catalyst particles comprising copper; and
a distribution of an iron-based catalyst disposed adjacent to the plurality of catalyst particles in a co-catalyst arrangement with the plurality of catalyst particles for the reduction of carbon dioxide (CO2) in the chemical cell.

17. The photocathode of claim 16 , wherein the iron-based catalyst comprises iron oxide.

18. The photocathode of claim 16 , wherein each conductive projection of the array of conductive projections comprises a respective nanowire.

19. The photocathode of claim 16 , wherein each catalyst particle of the plurality of catalyst particles is configured as a copper nanoparticle.

20. The photocathode of claim 16 , wherein each conductive projection of the array of conductive projections comprises a Group III-V semiconductor material.

21. A photoelectrochemical system comprising a working photocathode configured in accordance with the photocathode of claim 16 , and further comprising:
a counter electrode;
an electrolyte in which the working photocathode and the counter electrode are immersed; and
a voltage source that applies a bias voltage between the working photocathode and the counter electrode;
wherein the bias voltage establishes a preference for the reduction of carbon dioxide (CO2) at the working electrode toward methane.

22. A method of fabricating an electrode of an electrochemical system, the method comprising:
growing an array of conductive projections on a semiconductor substrate, each conductive projection of the array of conductive projections having a semiconductor composition for reduction of carbon dioxide (CO2) in the electrochemical system; and
depositing a catalyst arrangement along each conductive projection of the array of conductive projections, the catalyst arrangement comprising a copper-based catalyst and an iron-based catalyst for the reduction of carbon dioxide (CO2) in the chemical cell.

23. The method of claim 22 , wherein depositing the catalyst arrangement comprises implementing a number of electrodeposition cycles.

24. The method of claim 23 , wherein the number of electrodeposition cycles is about 10 cycles.

25. The method of claim 23 , wherein implementing the number of electrodeposition cycles comprises immersing the array of conductive projections in a solution, the solution comprising a copper precursor and an iron precursor.

Assignees

• Univ Michigan Regents

Inventors

• Ou Pengfei
• Song Jun
• Zhou Baowen
• Mi Zetian

Classifications

• B01J23/745

  Iron · CPC title

• C25B11/052

  Electrodes comprising one or more electrocatalytic coatings on a substrate · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• C25B11/02

  characterised by shape or form · CPC title

• C25B3/21

  Photoelectrolysis · CPC title