Nanostructured catalyst particle/catalyst carrier particle system

• US 6,680,279 B2
• Filed: 01/24/2002
• Issued: 01/20/2004
• Est. Priority Date: 01/24/2002
• Status: Expired due to Term

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Feng, Lee Lizhong, Ruthkosky, Martin S., Rogers, Jerry Dale, Cai, Mei
• Primary Examiner(s): Nguyen, Cam N.
• Application Number:
  US10/056,381
• Publication Number:
  US 20030139288A1
• Time in Patent Office: 726 Days
• Field of Search: 502/304, 502/303, 502/327, 502/329, 502/331, 502/332, 502/333, 502/334, 502/339, 502/342, 502/343, 502/346, 502/355, 502/415, 502/439
• US Class Current: 502/327
• CPC Class Codes: B01D 53/94 by catalytic processes
• CPC Class Codes: B01J 23/06 of zinc, cadmium or mercury
• CPC Class Codes: B01J 23/40 of the platinum group metals
• CPC Class Codes: B01J 23/72 Copper
• CPC Class Codes: B01J 35/23 in a colloidal state
• CPC Class Codes: B01J 35/30 characterised by their physical properties
• CPC Class Codes: B01J 35/392 Metal surface area
• CPC Class Codes: B01J 35/393 Metal or metal oxide crystallite size
• CPC Class Codes: B01J 35/40 characterised by dimensions, e.g. grain size in a colloidal state B01J35/23; crystallite size B01J35/77
• CPC Class Codes: B01J 35/58 Fabrics or filaments
• CPC Class Codes: B01J 35/613 10-100 m2/g
• CPC Class Codes: B01J 37/0009 Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst
• CPC Class Codes: B01J 37/0215 Coating
• CPC Class Codes: B01J 37/0221 of particles
• CPC Class Codes: B01J 37/04 Mixing B01J37/0009, B01J37/0018 take precedence

Abstract

A method of dispersing nanosized catalyst particles on the surface of larger catalyst carrier particles is disclosed. The coating process is done dry and yields high effective surface area of nanosized catalyst particles coated on the surface of catalyst carrier particles. In this process, nanosized catalyst particles and catalyst carriers are mechanically mixed in a high velocity and impact force environment to which catalyst particles are embedded, or filmed, on the surface of catalyst carrier particles without using water or any other additional chemicals. The catalyst composite structure produced comprises better coating uniformity of the catalyst particle on its catalyst carrier. The catalyst particle/catalyst carrier composite produced can be applied to a support structure, such as a monolith as readily used in automotive or other applications.

Claims

1. A process of making a composite of catalyst particles and catalyst carrier particles comprising:

dry coating catalyst particles with catalyst carrier particles such that the catalyst particles adhere to the surfaces of the catalyst carrier particles to form a composite catalyst particle/catalyst carrier particle material, said catalyst particles having diameters in the range of 1-500 nanometers, as dispersed on the carrier particles surface, and wherein said catalyst carrier particles either (a) having a median diameter that is at least ten times the median diameter of said catalyst particles, or (b) they are deposited on particles or fibers having a median diameter that is at least ten times the median diameter of said catalyst particles.

2. A process as recited in claim 1, wherein said catalyst particles comprise one or more noble metals and/or one or more metal oxides selected from the group consisting of copper oxide and zinc oxide.

3. A process as recited in claim 1, wherein said catalyst carrier particles comprise one or more oxides selected from the group consisting of aluminum oxide, cerium oxide, and lanthanum oxide.

4. A process as recited in claim 3, wherein said catalyst carrier particles are initially alumina particles having a surface area of at least 30 m²/g.

5. A process as recited in claim 1, wherein said catalyst particles and catalyst carrier particles are applied dry to a larger support fiber.

6. A process as recited in claim 1, wherein said catalyst particles are dry-coated to the surface of said catalyst carrier particles by repeatedly propelling a mixture of said particles at high velocity against an impact surface.

7. A process as recited in claim 1, wherein said catalyst particles are dry-coated to the surface of said catalyst carrier particles by continually shearing a mixture of said catalyst particles and said catalyst carrier particles between rotating surfaces.

8. A catalyst composite comprising catalyst particles having diameters in the range of 1-500 nanometers dry coated on the surface of larger catalyst carrier particles.

9. The catalyst composite as recited in claim 8, wherein said catalyst particles comprise one or more noble metals and/or one or more metal oxides selected from the group consisting of copper oxide and zinc oxide.

10. The catalyst composite as recited in claim 8, wherein said catalyst carrier comprises one or more oxides selected from the group consisting of aluminum oxide, cerium oxide, and lanthanum oxide.