Open mesh, random fiber, ceramic structure, monolithic catalyst support

• US 4,083,905 A
• Filed: 04/25/1975
• Issued: 04/11/1978
• Est. Priority Date: 04/25/1975
• Status: Expired due to Term

• Current Assignee: Champion Spark Plug Company (Apollo Global Management, Inc.)
• Original Assignee: Champion Spark Plug Company (Apollo Global Management, Inc.)
• Inventors: Rempes, Paul E. Jr., Nemeth, Joseph, Insley, Robert H.
• Primary Examiner(s): Arnold, Donald J.
• Assistant Examiner(s): Parrish, John A.
• Application Number:
  US05/571,602
• Time in Patent Office: 1,082 Days
• Field of Search: 264/43, 264/44, 264/60, 264/62, 264/131, 264/134, 264/63, 264/86, 264/137, 252/455 R, 252/449
• US Class Current: 502/436
• 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 37/0018 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 35/6316 Binders based on silicon compounds
• CPC Class Codes: C04B 38/06 by burning-out added substances by burning natural expanding materials or by sublimating or melting out added substances
• CPC Class Codes: C04B 38/0615 the burned-out substance being a monolitic element having approximately the same dimensions as the final article, e.g. a porous polyurethane sheet or a prepreg obtained by bonding together resin particles C04B38/0022 takes precedence
• CPC Class Codes: C04B 41/009 characterised by the material treated
• CPC Class Codes: C04B 41/5022 with vitreous materials composition of vitreous glazes and enamels C03C; ceramic pigments C09C1/0009
• CPC Class Codes: C04B 41/5025 with ceramic materials copper oxide or solid solutions thereof C04B41/5074
• CPC Class Codes: C04B 41/52 Multiple coating or impregnating multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation
• CPC Class Codes: C04B 41/86 Glazes; Cold glazes
• CPC Class Codes: C04B 41/89 for obtaining at least two superposed coatings having different compositions
• CPC Class Codes: Y10S 502/507 Synthetic resin, natural resin, polysaccaride, or polypeptide

Abstract

The present invention provides a novel cellular ceramic catalyst support. The support consists of a random-fiber ceramic framework having a high surface area. The support is fabricated by flocking an organic sponge with wood or textile fibers, and impregnating the flocked sponge with a high alumina slurry containing a silicone resin and a flux. The impregnated organic sponge is sintered at a high temperature to burn out the organic sponge material. A fired high-silica glaze can be applied to the sintered article, followed by a second sintering step. A second glaze containing from 10-25 parts by weight CuO and from 10-25 parts by weight ZrO₂, can be applied, followed by a 2000° F. sintering step. The high temperature causes recrystallization of the CuO onto the surface of the catalyst support thereby increasing the surface area. The glazed surface can be plated with copper or nickel and combinations thereof to function as a reducing unit in a catalytic converter. In addition, other reduction catalysts and oxidation catalysts, e.g., platinum are compatible with the support.

Claims

1. A method for producing a cellular ceramic catalyst support which comprises the steps of coating an open-celled organic sponge with an adhesive to produce a tacky surface, flocking the tacky surface with a material selected from the group consisting of rayon and cotton fibers and wood flour, impregnating the flocked organic sponge with a slurry having a viscosity of from 300 to 3000 centipoises and consisting essentially of from 50 to 90 percent by weight alumina, from 1/2 to 4 percent by weight of a flux and from 10 to 45 percent by weight silicone resin which consists essentially of a phenyl lower alkyl silicone resin wherein the total of phenyl and lower alkyl groups divided by the number of silicone atoms is from 0.9 to 1.5 and each alkyl group has not more than 4 carbon atoms, and sintering the impregnated organic sponge at a temperature between 2450°

-3100°

F. for a period of time sufficient to burn out the organic sponge material and to vitrify the slurry.

2. A method for producing a cellular ceramic catalyst support which comprises the steps of coating an open-called organic sponge with an adhesive to produce a tacky surface, flocking the tacky surface with a material selected from the group consisting of rayon and cotton fibers and wood flour, impregnating the flocked organic sponge with a slurry having a viscosity of from 300 to 3000 centipoises and consisting essentially of from 50 to 90 percent by weight alumina, from 1/2 to 4 percent by weight of a flux and from 10 to 45 percent by weight silicone resin which consists essentially of a phenyl lower alkyl silicone resin wherein the total of phenyl and lower alkyl groups divided by the number of silicone atoms is from 0.9 to 1.5 and each alkyl group has not more than 4 carbon atoms, sintering the impregnated organic sponge at a temperature between 2450°

-3100°

F. for a period of time sufficient to burn out the organic sponge material and to vitrify the slurry, coating the sintered article with a high silica glaze consisting essentially of from 60 to 80 parts by weight SiO₂, and from 2 to 15 parts by weight Al₂ O₃, the remainder being calcium, sodium and potassium oxides, and heating the article to a temperature of about 2700°

F. to provide thereon a glazed pore-free surface.

3. A method for producing a cellular ceramic catalyst support which comprises the steps of coating an open-celled organic sponge with an adhesive to produce a tacky surface, flocking the tacky surface with a material selected from the group consisting of rayon and cotton fibers and wood flour, impregnating the flocked organic sponge with a slurry having a viscosity of from 300 to 3000 centipoises and consisting essentially of from 50 to 90 percent by weight alumina, from 1/2 to 4 percent by weight of a flux and from 10 to 45 percent. by weight silicone resin which consists essentially of a phenyl lower alkyl silicone resin wherein the total of phenyl and lower alkyl groups divided by the number of silicone atoms is from 0.9 to 1.5 and each alkyl group has not more than 4 carbon atoms, and sintering the impregnated organic sponge at a temperature between 2450°

-3100°

F. for a period of time sufficient to burn out the organic sponge material and to vitrify the slurry, coating the sintered article with a high silica glaze consisting essentially of from 60 to 80 parts by weight SiO₂, and from 2 to 15 parts by weight Al₂ O₃, the remainder being calcium, sodium and potassium oxides, heating the article to a temperature of about 2700°

F. to provide thereon a glazed pore-free surface, coating the glazed article with a coating consisting essentially of from 60 to 80 parts by weight SiO₂, from 2 to 15 parts by weight Al₂ O₃, from 10 to 25 parts by weight CuO, and from 10 to 25 parts by weight ZrO₂, the remainder being calcium, sodium and potassium oxides, and heating the coated article to about 2100°

F. to provide thereon a textured surface.

4. A method for producing a cellular ceramic catalyst support which comprises the steps of coating an open-celled organic sponge with an adhesive to produce a tacky surface, flocking the tacky surface with a material selected from the group consisting of rayon and cotton fibers and wood flour, impregnating the flocked organic sponge with a slurry having a viscosity of from 300 to 3000 centipoises and consisting essentially of from 50-90 percent by weight alumina, from 1/2 to 4 percent by weight of a CaO-MgO flux, present in a ratio of 78 percent CaO and 22 percent MgO by weight, said flux being provided by CaCO₃ and MgCO₃, and from 10 to 45 percent by weight silicone resin which consists essentially of a phenyl lower alkyl silicone resin wherein the total of phenyl and lower alkyl groups divided by the number of silicon atoms is from 0.9 to 1.5 and each alkyl group has not more than 4 carbon atoms, sintering the impregnated organic sponge at a temperature between 2450°

-3100°

F. for a period of time sufficient to burn out the organic sponge material and to vitrify the slurry, coating the sintered article with a high silica glaze consisting essentially of from 60 to 80 parts by weight SiO₂, and from 2 to 15 parts by weight Al₂ O₃, the remainder being calcium, sodium and potassium oxides, heating the article to a temperature of about 2700°

F. to provide thereon a glazed pore-free surface, coating the glazed article with a coating consisting essentially of from 60 to 80 parts by weight SiO₂, from 2 to 15 parts by weight Al₂ O₃, from 10 to 25 parts by weight CuO, and from 10 to 25 parts by weight ZrO₂, the remainder being calcium, sodium and potassium oxides, and heating the coated article to about 2100°

F. to provide thereon a textured surface.

5. A method for producing a cellular ceramic catalyst support which comprises the steps of coating an open-celled organic sponge with an adhesive to produce a tacky surface, flocking the tacky surface with a material selected from the group consisting of rayon and cotton fibers and wood flour, impregnating the flocked organic sponge with a slurry having a viscosity of from 300 to 3000 centipoises and consisting essentially of about 60 percent by weight alumina, about 7 percent by weight SiO₂, from 1/2 to 4 percent by weight of a CaO-MgO flux, present in a ratio of 78 percent CaO and 22 percent MgO by weight, said flux being provided by CaCO₃ and MgCO₃, and about 28 percent by weight silicone resin which consists essentially of a phenyl lower alkyl silicone resin wherein the total of phenyl and lower alkyl groups divided by the number of silicon atoms is from 0.9 to 1.5 and each alkyl group has not more than 4 carbon atoms, and sintering the impregnated organic sponge at a temperature between 2450°

-3100°

F. for a period of time sufficient to burn out the organic sponge material and to vitrify the slurry, coating the sintered article with a high silica glaze consisting essentially of about 79 parts by weight SiO₂, and about 15 parts by weight Al₂ O₃, the remainder being calcium, sodium and potassium oxides, heating the article to a temperature of about 2700°

F. to provide thereon a glazed pore-free surface, coating the glazed article with a coating consisting essentially of about 47 parts by weight SiO₂, about 9 parts by weight Al₂ O₃, about 25 parts by weight CuO, and about 15 parts by weight ZrO₂, the remainder being calcium, sodium and potassium oxides, and heating the coated article to about 2100°

F. to provide thereon a textured surface.