Substrate having catalyst compositions on surfaces of opposite sides and method for producing the same

• US 20030054953A1
• Filed: 09/20/2001
• Published: 03/20/2003
• Est. Priority Date: 09/20/2001
• Status: Active Grant

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: He, Ting, Nomura, Tadashi, Kimura, Eisuke
• Granted Patent: US 7,326,669 B2
• Time in Patent Office: Days
• US Class Current: 502/302
• CPC Class Codes: B01D 53/885 Devices in general for catalytic purification of waste gases
• CPC Class Codes: B01J 19/0093 Microreactors, e.g. miniaturised or microfabricated reactors laboratory containers with capillary fluid transport in microfabricated channels or chambers B01L3/5027
• CPC Class Codes: B01J 2219/00783 Laminate assemblies, i.e. the reactor comprising a stack of plates
• CPC Class Codes: B01J 2219/00835 Comprising catalytically active material
• CPC Class Codes: B01J 2219/00873 Heat exchange
• CPC Class Codes: B01J 2219/2465 Two reactions in indirect heat exchange with each other
• CPC Class Codes: B01J 23/54 combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
• CPC Class Codes: B01J 23/63 with rare earths or actinides
• CPC Class Codes: B01J 35/56 Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
• CPC Class Codes: B01J 37/0215 Coating
• CPC Class Codes: B01J 37/0238 via the gaseous phase-sublimation
• CPC Class Codes: B01J 37/349 making use of flames, plasmas or lasers
• CPC Class Codes: C01B 2203/0227 containing a catalytic reforming step
• CPC Class Codes: C01B 2203/0283 containing a CO-shift step, i.e. a water gas shift step
• CPC Class Codes: C01B 2203/0811 by combustion of fuel
• CPC Class Codes: C01B 2203/1035 Catalyst coated on equipment surfaces, e.g. reactor walls
• CPC Class Codes: C01B 3/16 using catalysts
• CPC Class Codes: C01B 3/384 the catalyst being continuously externally heated
• CPC Class Codes: Y02P 20/52 using catalysts, e.g. selective catalysts

Abstract

A bi-laterally surfaced substrate in which the first surface consists of one or more than one of cerium oxide, aluminum oxide, tin oxide manganese oxide, copper oxide, cobalt oxide, nickel oxide, praseodymium oxide, terbium oxide, ruthenium, rhodium, palladium, silver, iridium, platinum and gold and the second surface consists of one or more than one of ruthenium, rhodium, palladium, silver, iridium, platinum and gold and micro channel micro component reactors including such substrates in a predetermined formed shape and methods for making the same utilizing a thermal spray on one side and a physical deposition process on the other side.

Claims

1. A substrate comprising first and second surfaces, the first surface consisting of one or more than one of cerium oxide, aluminum oxide, tin oxide, manganese oxide, copper oxide, cobalt oxide, nickel oxide, praseodymium oxide, terbium oxide, ruthenium, rhodium, palladium, silver, iridium, platinum and gold, the second surface consisting of one or more than one of ruthenium, rhodium, palladium, silver, iridium, platinum and gold.

2. The substrate of claim 1 in which the first surface comprises particles having a nominal diameter size distribution range of <

1 micron.

3. The substrate of claim 1 in which the second surface comprises a coating having a nominal thickness of <

100 nanometers.

4. The substrate of claim 1 or claim 2 or claim 3 comprising a thin metallic film having first and second surfaces.

5. The substrate of claim 4 comprising a nickel-based alloy.

6. The substrate of claim 1 including a plurality of folds.

7. The substrate of claim 6 in which the folds are spaced apart a predetermined distance corresponding to predetermined apexes in a folded member forming channels of a predetermined depth.

8. The substrate of claim 6 in which the folds are curvilinear.

9. The substrate of claim 6 in which the folds are angular.

10. The substrate of claim 6 in which the folds are formed in the substrate by stamping.

11. The substrate of claim 1 in which the first surface consists of ceria and palladium.

12. The substrate of claim 1 in which the second surface consists of palladium.

13. The substrate of claim 1 in which the first surface has a thickness in the nominal range of greater than approximately thirty microns (30 μ

m).

14. The substrate of claim 1 in which the first surface has a porosity of at least 50%.

15. The substrate of claim 1 in which the adhesion of the second surface tolerates a processing temperature up to approximately 1000°

C.

16. A method of providing different catalyst surfaces on the opposite surface sides of a substrate comprising:

thermal spraying one surface of the substrate with particulates of one or more than one of a metal hydroxide, metal carbonate, or metal nitrate particles and a noble metal, noble metal hydroxide, noble metal carbonate, or noble metal nitrate to produce a first catalyst composition thereon, and

coating a surface of the substrate opposite the one surface by a physical deposition process with one or more than one of ruthenium, rhodium, palladium, silver, iridium, platinum and gold to produce a second catalyst composition thereon.

17. The method of claim 16 in which a surface to be coated by a physical deposition process is cleaned by an ion-gun in an oxygen atmosphere and in an argon atmosphere prior to deposition.

18. The method of claim 16 wherein the substrate is supported upon a substantially rigid heat sink conforming to the shape of the substrate during the thermal spraying of the one surface.

19. The method of claim 16 in which the thermal spraying of the one surface precedes the physical deposition of a metal composition on the surface opposite the one surface.

20. The method of claim 16 in which coating the opposite surface of the substrate by a physical deposition process comprises an electron beam vapor deposition of a noble metal composition.

21. The method of claim 16 in which coating the opposite surface of the substrate by a physical deposition process comprises plasma sputtering a noble metal composition.

27. The method of claim 16 or claim 22 in which the one surface is grit-blasted prior to thermal spraying.

28. The method of claim 16 or claim 22 in which the physical deposition of a noble metal on the surface is performed subsequent to the thermal spraying of the one surface.

29. A micro component micro channel catalytic heat exchange device produced in accordance with claim 16 or claim 22.

22. A method of making a micro channel catalytic device comprising:

pre-forming a substrate with longitudinal folds spaced a predetermined distance apart corresponding to predetermined apexes of micro channels having a predetermined depth;

thermal spraying one surface of the substrate with particulates of one or more than one of a metal hydroxide, metal carbonate, or metal nitrate particles and a noble metal, noble metal hydroxide, noble metal carbonate, or noble metal nitrate to produce a first catalyst composition thereon;

coating the surface of the substrate opposite the one surface by a physical deposition process with one or more than one of ruthenium, rhodium, palladium, silver, iridium, platinum and gold to produce a second catalyst composition thereon.

23. The method of claim 22 for making a micro channel catalytic device further comprising the step of squeezing the substrate laterally such that the preformed folds of the substrate narrow from their apexes to form the micro channels.

24. The method of claim 22 in which the pre-forming of the substrate with longitudinal folds comprises stamping the folds into a sheet material.

25. The method of claim 22 in which the preformed substrate is supported during the step of thermal spraying in contact with a substantially rigid heat sink having an upper surface with a shape corresponding to the supported side of the pre-folded substrate.

26. The method of claim 22 further including brazing the apexes of the folds on each side of the substrate to a plate to form enclosed channels defined by the apexes of the folds.