Solar fuels generator

• US 10,344,387 B2
• Filed: 10/24/2016
• Issued: 07/09/2019
• Est. Priority Date: 04/02/2012
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Lewis, Nathan S., Spurgeon, Joshua M.
• Primary Examiner(s): Smith, Nicholas A
• Assistant Examiner(s): Raphael, Colleen M
• Application Number:
  US15/332,236
• Publication Number:
  US 20170037523A1
• Time in Patent Office: 988 Days
• CPC Class Codes: C25B 1/04 by electrolysis of water
• CPC Class Codes: C25B 1/55 Photoelectrolysis
• CPC Class Codes: C25B 13/02 characterised by shape or form
• CPC Class Codes: C25B 9/19 with diaphragms
• CPC Class Codes: C25B 9/73 of the filter-press type
• CPC Class Codes: Y02E 60/36 Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Abstract

The solar fuels generator includes an ionically conductive separator between a gaseous first phase and a second phase. A photoanode uses one or more components of the first phase to generate cations during operation of the solar fuels generator. A cation conduit is positioned provides a pathway along which the cations travel from the photoanode to the separator. The separator conducts the cations. A second solid cation conduit conducts the cations from the separator to a photocathode.

Claims

1. A solar fuels generator, comprising:

an ionically conductive separator between a first phase and a second phase;

a photoanode that uses one or more components of the first phase to generate cations during operation of the solar fuels generator;

a photocathode exposed to the second phase; and

a cation conduit positioned so as to provide a pathway along which the cations travel from the photoanode to the separator

wherein the photoanode extends outward from a first side of the ionically conductive separator into the first phase and the photocathode extends outward from a second side of the ionically conductive separator into the second phase, the second side being opposite from the first side.

2. The generator of claim 1, wherein the photoanode includes an oxidation catalyst.

3. The generator of claim 1, wherein the pathway extends from the oxidation catalyst to the separator.

4. The generator of claim 1, wherein the cation conduit is in direct physical contact with the separator.

5. The generator of claim 1, wherein the photoanode includes an oxidation catalyst between the cation conduit and a side of the photoanode.

6. The generator of claim 1, wherein the cation conduit is in direct physical contact with the separator and extends outward from the separator along a side of the photoanode.

7. The generator of claim 1, wherein the photoanode is one of a plurality of photoanodes that each uses one or more components of the first phase to generate cations during operation of the solar fuels generator.

8. The generator of claim 1, wherein the cation conduit is the same material as the separator.

9. The generator of claim 1, wherein the cation conduit is the same material as the separator and the cation conduit is continuous with the separator.

10. The generator of claim 1, wherein the first phase is a gas that includes water vapor, the second phase is a gas, and the photoanode is configured to use the water vapor to generate the cations.

11. The generator of claim 1, wherein the cation conduit includes a copolymer of a substituted or unsubstituted alkylene and an acid.

12. The generator of claim 11, wherein the acid is a sulfonic acid.

13. The generator of claim 1, wherein the separator conducts the cations.

14. The generator of claim 1, wherein the pathway extends from the separator to a portion of the photoanode that is distant from the separator.

15. The generator of claim 1, wherein:

the photocathode generates the solar fuel in the second phase, and

a second cation conduit positioned so as to conduct cations conducted through the separator from the separator to a portion of the photocathode that is spaced apart from the separator.

16. The generator of claim 15, wherein the photocathode includes a reduction catalyst between the second cation conduit and a side of the photocathode.

17. The generator of claim 15, wherein the second cation conduit is in direct physical contact with the separator and extends outward from the separator along the lateral side of the photocathode.

18. A solar fuels generator, comprising:

an ionically conductive separator between a first phase and a second phase;

a photoanode contacting the first phase;

a photocathode that uses cations generated from the first phase to generate the solar fuel in the second phase; and

a cation conduit positioned so as to provide a pathway along which cations generated at the photoanode can travel from the separator to the photocathode

wherein the photoanode extends outward from a first side of the ionically conductive separator into the first phase and the photocathode extends outward from a second side of the ionically conductive separator into the second phase, the second side being opposite from the first side.

19. A method of generating solar fuels, comprising:

generating a cation at a photoanode in a gaseous first phase; and

conducting the generated cation through a cation conduit to an ionically conducting separator located between the first phase and a second phase, wherein a photocathode uses the cations generated from the first phase to generate the solar fuel in the second phase and wherein the photoanode extends outward from a first side of the ionically conductive separator into the first phase and the photocathode extends outward from a second side of the ionically conductive separator into the second phase, the second side being opposite from the first side.