Method for producing substrate having catalyst compositions on surfaces of opposite sides

• US 8,304,030 B2
• Filed: 10/09/2007
• Issued: 11/06/2012
• Est. Priority Date: 09/20/2001
• Status: Expired due to Fees

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: He, Ting, Kimura, Eisuke, Nomura, Tadashi
• Primary Examiner(s): Bareford, Katherine A
• Application Number:
  US11/869,213
• Publication Number:
  US 20080075877A1
• Time in Patent Office: 1,855 Days
• Field of Search: 427/450
• US Class Current: 427/450
• 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 method of providing different catalyst surfaces on the opposite surface sides of a metal substrate comprising:

thermal spraying one surface of the substrate with a mixture of powders having a size greater than 10 micrometers and no more than 200 micrometers comprising

     1) one or more than one of a hydroxide, carbonate, or nitrate of one or more than one of cerium, aluminum, tin, manganese, copper, cobalt, nickel, praseodymium or terbium and

     2) one or more than one of a noble metal, noble metal hydroxide, noble metal carbonate, or noble metal nitrate onto the surface of the substrate such that the particles in the mixture decompose by pyrolysis to produce a mixture of, respectively on the one surface a distribution of particles of an oxide of one or more than one of cerium, aluminum, tin, manganese, copper, cobalt, nickel, praseodymium or terbium and particles of one or more than one of ruthenium, rhodium, palladium, silver, iridium, platinum and gold, such that the sprayed mixture results in particles bonded to the surface where approximately 90% have a size less than 5 microns (μ

m); and

, subsequent to the thermal spraying, coating the surface of the substrate opposite the one surface by a physical vapor deposition process with one or more than one of ruthenium, rhodium, palladium, silver, iridium, platinum and gold.

2. The method of claim 1 in which the surface to be coated by a physical vapor deposition process opposite the first surface is cleaned by an ion-gun first in an oxygen atmosphere and then in an argon atmosphere.

3. The method of claim 1 wherein the substrate is supported upon a rigid heat sink conforming to the shape of the substrate during the thermal spraying of the one surface.

4. The method of claim 1 in which coating the opposite surface of the substrate with one or more than one of ruthenium, rhodium, palladium, silver, iridium, platinum and gold by a physical vapor deposition process comprises plasma sputtering of the one or more than one of ruthenium, rhodium, palladium, silver, iridium, platinum and gold.

5. The method of claim 1 wherein approximately 90% the particles in the mixture bonded to the one side have a size less than one micron.

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

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

thermal spraying a surface of the pre-formed substrate with a powder mixture of

     1) metal oxide precursors comprising particulates of one or more than one of a hydroxide, carbonate, or nitrate of one or more than one of cerium, aluminum, tin, manganese, copper, cobalt, nickel, praseodymium or terbium and

     2) one or more than one of a metal, metal hydroxide, metal carbonate, or metal nitrate of one or more than one of ruthenium, rhodium, palladium, silver, iridium, platinum and gold, the mixture of powders having a size greater than 10 micrometers and no more than 200 micrometers, to produce on the surface, respectively, an oxide composition of a mixture of

     1) one or more than one of cerium, aluminum, tin, manganese, copper, cobalt, nickel, praseodymium or terbium and

     2) one or more than one of ruthenium, rhodium, palladium, silver, iridium, platinum or gold, whereby in the thermal spraying, the powder mixture decomposes and the composition sprayed on the surface is bonded to the surface and where approximately 90% of the particles of the composition so bonded have a size less than 5 microns (μ

m); and

, subsequent to the thermal spraying, coating the surface of the substrate opposite the first surface by a physical vapor deposition process with one or more than one of ruthenium, rhodium, palladium, silver, iridium, platinum and gold.

7. The method of claim 6 for making a micro channel catalytic device wherein the step of pre-forming comprises longitudinally squeezing the substrate laterally such that the preformed folds of the substrate compress from their apexes to form micro channels.

8. The method of claim 6 wherein pre-forming the substrate with longitudinal folds comprises stamping the folds into a sheet material.

9. The method of claim 6 in which the preformed substrate is supported during the step of thermal spraying in contact with a rigid heat sink having an upper surface with a shape corresponding to the supported side of the pre-folded substrate.

10. The method of claim 6 further including, after the steps of thermal spraying and physical vapor deposition, 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.

11. A method of making a micro channel catalytic device in accordance with claim 6 including the further steps of 1) squeezing, after the deposition of a catalytic material thereon, the preformed metal shape from opposite lateral sides to compress the longitudinal separations between the folds to form a wavy plate separator;

2) enclosing the wavy plate between a set of upper and lower plates to form enclosed channels of a micro reactor assembly that are defined by the apexes on the opposite sides of the squeezed preformed shape; and

     3) brazing the apexes of the squeezed shape to the upper and lower plates.

12. The method of claim 6 wherein approximately 90% the particles in the mixture bonded to the one side have a size less than one micron.