Method of forming robust metal, metal oxide, and metal alloy layers on ion-conductive polymer membranes

• US 6,077,621 A
• Filed: 01/06/1998
• Issued: 06/20/2000
• Est. Priority Date: 01/22/1997
• Status: Expired due to Term

• Current Assignee: BASF Fuel Cell GmbH (BASF SE)
• Original Assignee: De Nora S.p.A. (Industrie De Nora S.p.A)
• Inventors: Allen, Robert J., Giallombardo, James R.
• Primary Examiner(s): Nuzzolillo, Maria
• Assistant Examiner(s): Ruthkosky, Mark
• Application Number:
  US09/003,228
• Time in Patent Office: 896 Days
• Field of Search: 429/30, 427/38, 134/1, 134/33, 156/643, 361/504
• US Class Current: 429/524
• CPC Class Codes: C23C 14/022 by means of bombardment with energetic particles or radiation
• CPC Class Codes: C23C 14/20 on organic substrates
• CPC Class Codes: C25B 9/23 comprising ion-exchange membranes in or on which electrode material is embedded
• CPC Class Codes: G01N 27/404 Cells with anode, cathode and cell electrolyte on the same side of a permeable membrane which separates them from the sample fluid , e.g. Clark-type oxygen sensors
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 4/8817 Treatment of supports before application of the catalytic active composition coated porous composites H01M8/0245
• CPC Class Codes: H01M 4/8867 Vapour deposition
• CPC Class Codes: H01M 8/1004 characterised by membrane-electrode assemblies [MEA] H01M8/12 takes precedence
• CPC Class Codes: H01M 8/1009 with one of the reactants being liquid, solid or liquid-charged H01M8/12 takes precedence
• CPC Class Codes: H01M 8/1016 characterised by the electrolyte material H01M8/12 takes precedence
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

The invention is to a dual beam process for providing an ion-conducting membrane with a thin metal or metal-oxide film. The process includes the cleaning of a membrane surface with a low energy electron beam followed by the deposition of the metal or metal-oxide film by a high energy electron beam of ions.

Claims

1. A dual beam assisted deposition process for the purpose of an ion-conducting membrane provided with a thin metal or metal oxide film comprising subjecting the ion-conductive membrane under vacuum to an electron beam having an energy less than 500 eV to clean the membrane surface and subjecting the cleaned membrane under vacuum to a beam having an energy between 500 to 2000 eV and containing ions of the metal to be deposited to form the metal or metal oxide film.

2. The process of claim 1 wherein the metal to be deposited is platinum.

3. The process of claim 1 wherein the metal oxide to be deposited is tungsten oxide.

4. The process of claim 1 wherein the metal to be deposited is an alloy of platinum group metals.

5. A metallized membrane structure produced by the process of claim 1.

6. The membrane of claim 5 wherein the metal film is highly porous.

7. The membrane of claim 5 wherein the metal film is highly dense and impervious.

8. The membrane of claim 5 wherein the metal or metal oxide is a platinum group metal.

9. The membrane of claim 8 wherein the metal is platinum.

10. The membrane of claim 8 wherein the metal oxide is tungsten oxide.

11. In a fuel cell with an anode and a cathode separated by an ion-conductive membrane, the improvement consisting of using a membrane of claim 5 as the anode-membrane.

12. The fuel cell of claim 11 wherein the membrane is provided with a platinum metal film.

13. The fuel cell of claim 11 wherein the membrane is provided with a tungsten oxide film.

14. In a process of oxidizing methanol at the anode and reducing oxygen at the cathode in a fuel cell, the improvement comprising using the fuel cell of claim 11 wherein the film is impervious to methanol transport.

15. The process of claim 14 wherein the film is tungsten oxide film.