Methods of indirect electrochemistry using ionomer coated electrodes

• US 5,399,245 A
• Filed: 09/03/1993
• Issued: 03/21/1995
• Est. Priority Date: 09/03/1993
• Status: Expired due to Fees

• Current Assignee: North Carolina State University (University of North Carolina System)
• Original Assignee: North Carolina State University (University of North Carolina System)
• Inventors: Fedkiw, Peter S. Jr.
• Primary Examiner(s): Niebling, John
• Assistant Examiner(s): Mee, Brendan
• Application Number:
  US08/116,338
• Time in Patent Office: 564 Days
• Field of Search: 204/105 R, 204/290 R, 204/282, 204/97, 204/94, 204/112, 204/78, 204/59 R, 204/86
• US Class Current: 205/334
• CPC Class Codes: C25B 1/00 Electrolytic production of inorganic compounds or non-metals
• CPC Class Codes: C25B 9/23 comprising ion-exchange membranes in or on which electrode material is embedded

Abstract

Novel methods of indirect electrochemistry are provided. The methods use ionomer coated electrodes for regeneration of the redox reagent in the indirect electrochemical process. The electrode may be either directly coated with a thin ionomer coating, or alternatively may electrodeposited within an ionomer coated electronically conductive substrate. Ionomers used to coat the electrodes of the subject method include Nafion® and Tosflex®.

Claims

1. A method of indirect electrochemistry, said method comprising the steps of:

contacting an aqueous phase with an organic phase, wherein said aqueous phase comprises a redox reagent and said organic phase comprises an organic reactant, to form a spent redox reagent and a product;

separating said aqueous phase from said organic phase; and

contacting said aqueous phase with an electrode coated with an ionomer film and a counter electrode, wherein the potential between said ionomer coated electrode and counter electrode is sufficient to regenerate said spent redox reagent at said ionomer coated electrode;

whereby said spent redox reagent is converted to said redox reagent.

2. The method according to claim 1, wherein said ionomer film is cationic.

3. The method according to claim 2, wherein said ionomer film is a cationic perfluorinated membrane.

4. The method according to claim 1, wherein said ionomer film is anionic.

5. The method according to claim 4, wherein said ionomer film is an anionic perfluorinated membrane.

6. The method according to claim 1, wherein said ionomer film comprises a hybrid film of anionic and cationic constituents.

7. The method according to claim 6, wherein said hybrid film comprises a cationic perfluorinated membrane and an anionic perfluorinated membrane.

8. The method according to claim 1, wherein said ionomer film coats said electrode in a thickness ranging from about 0.01 μ

m to 10 μ

m.

9. The method according to claim 7, wherein said electrode is platinum.

10. The method according to claim 7, wherein said ionomer film is a cationic perfluorinated membrane.

11. The method according to claim 7, wherein said ionomer film is an anionic perfluorinated membrane.

13. The method according to claim 1, wherein said electrode comprises:

a substrate;

an ionomer film coating said substrate; and

electrodes electrodeposited within said ionomer film, wherein said electrodes are anchored to said substrate.

14. A method according to claim 13, wherein said substrate comprises an electronically conductive substrate.

15. A method according to claim 13, wherein said ionomer film is a cationic perfluorinated membrane.

16. A method according to claim 13, wherein said electrode comprises platinum.

12. A method of indirect electrochemistry, said method comprising the steps of:

contacting an aqueous phase comprising a redox reagent and an organic phase comprising an organic reactant to form a spent redox reagent and product;

separating said aqueous phase from said organic phase; and

contacting said aqueous phase with a cationic perfluorinated membrane coated platinum electrode, wherein the thickness of said cationic perfluorinated membrane coating ranges from about 0.01 μ

m to 10 μ

m, and a counter electrode, wherein the potential between said cationic perfluorinated membrane coated electrode and counter electrode is sufficient to regenerate said spent redox reagent at said cationic perfluorinated membrane coated electrode;

whereby said spent redox reagent is converted to said redox reagent.

17. A method of indirect electrochemistry, said method comprising the steps of:

contacting an aqueous phase comprising a redox reagent and an organic phase comprising an organic reactant to form a spent redox reagent and product;

separating said aqueous phase from said organic phase; and

contacting said aqueous phase to an ionomer coated electrode and a counter electrode, wherein the potential between said ionomer coated electrode and counter electrode is sufficient to regenerate said spent redox reagent at said electrode, wherein said ionomer coated electrode comprises an electronically conductive substrate, a cationic perfluorinated membrane film and an electrode, wherein said electrode is electrodeposited in said cationic perfluorinated membrane film and anchored to said electronically conductive substrate;

whereby said spent redox reagent is converted to said redox reagent.