Heme protein immobilized electrode and its use

• US 4,541,908 A
• Filed: 08/31/1984
• Issued: 09/17/1985
• Est. Priority Date: 06/12/1981
• Status: Expired due to Fees

• Current Assignee: Ajinomoto Co., Inc.
• Original Assignee: Ajinomoto Co., Inc.
• Inventors: Nakamura, Asao, Inokuchi, Hiroo, Yagi, Tatsuhiko, Niki, Katsumi
• Primary Examiner(s): Andrews, R. L.
• Application Number:
  US06/646,072
• Time in Patent Office: 382 Days
• Field of Search: 204/129, 204/290 R, 204/291, 204/101, 204/DIG. 4, 204/294, 429/43, 427/414
• US Class Current: 205/334
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: C25B 11/04 characterised by the material
• CPC Class Codes: H01M 4/9008 Organic or organo-metallic compounds
• CPC Class Codes: H01M 8/16 Biochemical fuel cells, i.e. cells in which microorganisms function as catalysts
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10S 204/04 Electrolysis cell combined with fuel cell

Abstract

An electrical conducting solid electrode on the surface of which cytochrome c₃ is immobilized in an amount ranging from 20%-100% of the monolayer coverage, said electrode thereby provided with the electrocatalytic capability of the direct four-electron reduction of dioxygen to water, and its uses.

Claims

1. An electrode comprising a solid electrical conducting material on the surface of which cytochrome c₃ is immobilized in an amount ranging between 20% and 100% of monolayer coverage.

4. A method of electrolysis of water to oxygen and hydrogen with the use of the electrode as claimed in claim 1 which comprises

placing said electrode into a first aqueous electrolyte solution,

placing a second electrode into a second aqueous electrolyte solution, said second electrolyte solution and said electrode being in communication with said first electrolyte solution and said first electrode in a manner to complete an electrical circuit, and

applying an electrical current to said circuit sufficient to cause electrolysis of water to oxygen and hydrogen.

5. A method of producing hydrogen which comprises placing an electrode as set forth in claim 1 in a mixed solution comprising (1) a buffer solution and (2) an electrolyte solution containing a redox compound which couples with cytochrome c₃ in a hydrogen evolution reaction, and

placing a second electrode into a second aqueous electrolyte solution, said second electrolyte solution and said second electrode being in communication with said first electrolyte solution and said mixed solution in a manner to complete an electrical circuit, and

applying an electrical current to said circuit sufficient to cause hydrogen evolution at the first electrode.

6. The method of claim 5, wherein said redox compound which couples with cytochrome c₃ is hydrogenase, nitrogenase or a ferredoxin.

7. A method of dissociating hydrogen which comprises placing an electrode as set forth in claim 1 as a hydrogen electrode in a mixed solution comprising (1) a buffer solution and (2) an electrolyte solution containing a redox compound which couples with cytochrome c₃ in a hydrogen dissociation reaction and

placing a second electrode into a second aqueous electrolyte solution, said second electrolyte solution and said second electrode being in communication with said first electrolyte solution and said first electrode in a manner to complete an electrical circuit, and

applying an electrical current to said circuit sufficient to cause dissociation of hydrogen at the first electrode.

8. The method of claim 7, wherein said redox compound which couples with cytochrome c₃ is hydrogenase, nitrogenase or a ferredoxin.

9. The method of claim 7, wherein said hydrogen electrode is an anode of a fuel cell.

2. A method of catalytic four-electron reduction of dioxygen directly to water in an aqueous solution which comprises placing an oxygen electrode comprising a solid electrical conducting material on the surface of which cytochrome c₃ is immobilized in an amount ranging between 20% and 100% of monolayer coverage into a first aqueous electrolyte solution at a pH of from about 4 to 10, placing a second electrode into a second aqueous electrolyte solution, said second electrolyte solution and second electrode being in communication with said first electrolyte solution and said first electrode in a manner to complete an electrical circuit, and

applying an electrical current to said circuit sufficient to cause reduction of oxygen to water at the first electrode.

3. The method as claimed in claim 2 in which said oxygen electrode is a carbon electrode on the surface of which cytochrome c₃ is immobilized in an amount ranging from 40% to 70% of monolayer coverage, said cytochrome c₃ being isolated from a microorganism of the genus Desulfovibrio which is capable of producing cytochrome c₃.

10. An electrode comprising a solid electrical conducting material on the surface of which cytochrome C₃ is immobilized in an amount ranging from about 20%-100% of monolayer coverage which is prepared by soaking said electrode in a solution comprising cytochrome C₃ in a concentration of from about 10^-5 M to 10^-3 M.

11. An electrode comprising a solid electrical conducting material on the surface of which cytochrome C₃ is immobilized in an amount ranging from about 20%-100% of monolayer coverage which is further treated by:

(a) soaking the electrode in a solution comprising hydrogenase, and

(b) activating the hydrogenase.

12. The electrode of claim 11 wherein the cytochrome C₃ is immobilized by irreversible adsorption onto the electrode.

13. The electrode of claim 11 wherein the cytochrome C₃ is immobilized by covalent bonding.

14. The electrode of claim 13 wherein the covalent bonding is effected with polyvinylpyridine.

15. An electrode comprising a solid electrical conducting material on the surface of which cytochrome C₃ is immobilized in an amount ranging from about 20-100 percent of monolayer coverage which is prepared by:

(a) soaking the electrode in a mixed solution containing cytochrome C₃ and hydrogenase, and

(b) activating the hydrogenase.

16. The electrode of claim 15 wherein the hydrogenase is activated by means of bubbling hydrogen gas.

17. The electrode of claim 15 wherein the concentration of cytochrome C₃ in the mixed solution is approximately 10^-5 M.