Method of manufacturing monolithic catalysts
AssigneeBASF Catalysts LLC
InventorsJoseph C. Dettling, Victor Rosynsky, Chung-Zong Wan
Life of this patent
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Abstract
The present invention is directed to a method of coating a substrate, such as a honeycomb having a plurality of parallel channels defined by the honeycomb walls. The honeycomb has different zones along the length of the channels. The zones are defined by their coating (or lack of coating) and extend for a length of the channel in which there is the same coating and architecture. Soluble components in coating compositions are fixed in their respective zones by forcing a heated gas stream through the channels.
Claims21
A method of coating a substrate comprising an inlet end, an outlet end, wall elements extending between the inlet end to the outlet end and a plurality of axially enclosed channels defined by the wall elements, at least some of the channels having a channel inlet at the inlet end and a channel outlet at the outlet end, the method comprising:
- passing at least a first inlet fluid composition into the inlet end of the substrate to form at least a first inlet end layer on the walls and extending for only part of the length from the inlet end toward the outlet end, the first inlet fluid composition comprising at least one first inlet base metal oxide component and at least one first inlet precious metal component;
- and
- applying a vacuum to the outlet end while forcing a heated gas stream through the channels from the inlet end after the formation of each inlet end layer without significantly changing the length of each inlet layer, wherein the temperature of the heated gas is from about 200° C. to about 400° C. to fix the first inlet precious metal component.
A method for coating a substrate comprising an inlet end, an outlet end, axial wall elements extending from the inlet end to the outlet end and a plurality of axially enclosed channels defined by the wall elements, with at least some of the channels having a channel inlet at the inlet end and a channel outlet at the outlet end, comprising:
- partially immersing the substrate at the inlet end into a vessel containing a first coating composition containing a soluble component, at least once, to form at least one first layer located on the walls and extending for at least part of the length from the inlet end toward the outlet end, with at least one inlet end coating extending for only part of the length from the inlet end toward the outlet end;
- partially immersing the substrate at the outlet end into a vessel containing a second coating composition containing a soluble component, at least once, to form at least one second layer located on the walls and extending for at least part of the length from the outlet end toward the inlet end;
- and
- thermally treating the substrate after each immersion step, to form at least two zones, a first zone extending from the inlet end and a second zone, each extending along the channels wherein the second zone extends along a separate length of the channel than the first zone, the thermal treatment fixing the soluble component of the first zone in the first zone and the soluble component of the second zone in the second zone,
- wherein the thermal treatment comprises applying a vacuum to one of the inlet end or the outlet end while forcing a heated gas stream through the channels from the other of the inlet end or the outlet end after the formation of each layer without significantly changing the length of each layer, wherein the temperature of the heated gas is from about 200° C. to about 400° C.
Dependencies are inferred from the claim text.