Porous ceramics-exhaust oxidation catalyst

• US 3,926,851 A
• Filed: 07/17/1973
• Issued: 12/16/1975
• Est. Priority Date: 10/22/1970
• Status: Expired due to Term

• Current Assignee: W R Grace & Company - CONN (Standard Industries Holdings, Inc.)
• Original Assignee: Francis J. Sergeys
• Inventors: Sergeys, Francis J.
• Primary Examiner(s): Shaver, Paul F.
• Application Number:
  US05/380,032
• Time in Patent Office: 882 Days
• Field of Search: 252/455R,463,465,466PR,471,477R
• US Class Current: 502/84
• CPC Class Codes: B01D 53/86 Catalytic processes
• CPC Class Codes: B01D 53/865 characterised by a specific catalyst
• CPC Class Codes: B01D 53/8653 characterised by a specific device
• CPC Class Codes: B01J 23/868 copper and chromium
• CPC Class Codes: B01J 37/0018 Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat)
• CPC Class Codes: C04B 35/00 Shaped ceramic products characterised by their composition porous ceramic products C04B38/00; ceramic articles characterised by particular shape, see the relevant classes, e.g. linings for casting ladles, tundishes, cups or the like B22D41/02; ceramic substrates for microelectronic semi-conductors H01L23/15; Ceramics compositions containing free metal bonded to carbides, diamond, oxides, borides, nitrides, silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides or sulfides other than as macroscopic reinforcing agents C22C; shaping of ceramics B28B; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products chemical preparation of powders of inorganic compounds C01; infiltration of sintered ceramic preforms with molten metal C04B41/51
• CPC Class Codes: C04B 38/0006 Honeycomb structures from one or more corrugated sheets by winding or stacking C04B38/0083
• CPC Class Codes: C04B 38/0083 from one or more corrugated sheets or sheets bearing protrusions by winding or stacking
• CPC Class Codes: C04B 38/04 by dissolving-out added substances
• CPC Class Codes: C04B 38/062 the burned-out substance being formed in situ, e.g. by polymerisation of a prepolymer composition containing ceramic powder
• CPC Class Codes: C08J 2201/0542 from an organic solvent-based polymer composition
• CPC Class Codes: C08J 9/28 by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum
• CPC Class Codes: Y10S 502/524 Spinel

Abstract

Method of preparing temperature resistant exhaust oxidation catalysts suitable for use in land vehicle exhaust systems comprising a porous ceramic base impregnated with suitable oxidizing agents and the resulting catalysts. The porous ceramic base is prepared from a ceramic powder filled, plasticized polyolefin.

Claims

1. A PROCESS FOR PREPARING AN ENGINE EXHAUST CATALYST COMPRISING THE FOLLOWING STEPS:

A. HOMOGENEOUSLY BLENDING A COMPOSITION CONSISTING ESSENTIALLY OF 15-80 VOLUME PERCENT OF A POLYOLEFIN HAVING A MOLECULAR WEIGHT OF AT LEAST 150,000 AND A STANDARD LOAD MELT INDEX OF SUBSTANTIALLY ZERO, 5-67 VOLUME PERCENT OF A CERAMIC FILLER, SELECTED FROM THE GROUP CONSISGING OF ALUMINA, MULLITE, ZERCON MULLITE, MAGNESIUM ALUMINATE SPINEL, AND CORDIERITE, AND 15-80 VOLUME PERCENT OF A PLASTICIZER SELECTED FROM THE GROUP CONSISTING OF MINERAL OILS, DIETHYLENE GLYCOL, PROPYLENE GLYCOL, DIPROPYLENE GLYCOL GLYCERINE, AND A GLYCEROL MONOACETATE, TRIMETHYLENE GLYCOL, TETRAMETHYLENE GLYCOL, 2, 3-BUTYLENE GLYCOL, TRIETHYLENE PHOSPHATE, POLYVINYL ALCOHOL, AND POLYVINYL PYRROLIDONE, B. HEATING SAID COMPOSITION TO ABOUT 125* TO 175*C., MOLDING TO FORM A PLASTIC SHEET AND IMPRESSING RIBS THEREON, C. ROLLING SAID PLASTIC SHEET SO THAT SAID RIBS CONTACT SAID SHEET, HEATING TO 150*C. TO JUST BELOW THE BURN OFF POINT TO FUSE THE CONTACTING AREAS TOGETHER THERMOPLASTICALLY, D. EXTRACTING SAID PLASTICIZER WITH WATER OR AN ORGANIC SOLVENT,

2. The process according to claim 1, wherein said polyolefin is selected from the group consisting of polyethylene, and polypropylene, the plasticizer is mineral oil and the plasticizer is removed by contacting the fused structure with hexane.

3. REMOVING SAID POLYOLEFIN BY HEATING TO 240* TO 700*C. TO FORM A POROUS CERAMIC STRUCTURE, AND TO BURN OFF THE POLYOLEFIN AND, F. FIRING SAID POROUS CERAMIC STRUCTURE AT A TEMPERATURE OF 1300* TO 1450*F. FOR ABOUT 2 HOURS TO SINTER SAID POROUS CERAMIC STTUCTURE, G. COATING THE CERAMIC STRUCTURE WITH SOLUTIONS OF SALTS OF METALS SELECTED FROM THE GROUP CONSISTING OF THE NOBLE METALS AND COPPER, CHROMIUM AND MANGANESE AND HEATING TO REDUCE THE NOBLE METAL SALTS TO THE METAL OR CONVERT THE COPPER CHROMIUM AND MANGANESE SALTS TO THE OXIDES