Porous ceramic filters with catalyst coatings
AssigneeCorning Incorporated
InventorsTinghong Tao, Jianguo Wang
Life of this patent
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Abstract
Porous ceramic catalyst supports or filters to be provided with catalyst coatings via oxide washcoating processes are pre-coated with cross-linked polymer barrier layers to prevent washcoat nanoparticle intrusion into the microcracked and/or microporous surfaces of the ceramics, the barrier coatings being formed by thermally cross-linking hydrocarbon polymers that are vaporizable at moderate washcoat stabilization or catalyst activation temperatures and being preferentially.
Claims7
A method for providing a barrier coating on a porous ceramic article which comprises the steps of:
- applying to the porous ceramic article a polymer solution or dispersion comprising a liquid vehicle, a cross-link promoter and a water-soluble, thermally cross-linkable, thermally pyrolyzable hydrocarbon polymer selected from the group consisting of amine-functional ionene polymers, polyvinyl alcohol, polyacrylic acid, and polyacrylic amine;
- and
- heating the ceramic article to a temperature sufficient to substantially remove the vehicle from the applied solution or dispersion and to effect cross-linking of the hydrocarbon polymer.
A method for applying a catalyst or catalyst washcoat to a ceramic catalyst support comprising the steps of:
- applying to the catalyst support a polymer solution or dispersion comprising a liquid vehicle, a cross-link promoter, and a thermally cross-linkable, thermally pyrolyzable hydrocarbon polymer;
- heating the ceramic article to a temperature sufficient to substantially remove the vehicle from the applied solution or dispersion and to effect cross-linking of the hydrocarbon polymer to thereby provide a polymer-coated support;
- applying to the polymer-coated support an aqueous washcoating or catalyst coating and drying the coating or washcoating to provide a catalyst-coated or washcoated support;
- and
- heating the catalyst-coated or washcoated support to a temperature at least sufficient to remove the cross-linked polymer coating.
Dependencies are inferred from the claim text.