Patent ID: 8889227

Claim:
A method for preparing monolithic catalyst washcoat, characterized in that the method comprises: preparing a coating slurry by using coating material and water as raw material, wherein the range of average particle diameter of the coating material of the coating slurry is from 20 nm to 10 um, and the viscosity is 10-40 mPa·S; pretreating a monolithic honeycomb carrier by drying or calcining; placing the monolithic honeycomb carrier into a hermetic container; and vacuuming the hermetic container to 0.01 Pa-0.05 MPa; using a nozzle of a coating slurry tank disposed on the hermetic container to apply the prepared coating slurry into channels in the monolithic honeycomb carrier from the top of the monolithic honeycomb carrier by vacuum spraying under vacuum and then placing the monolithic honeycomb carrier at rest about 1-15 minutes under the vacuum, wherein processes of applying the prepared coating slurry and placing the monolithic honeycomb carrier are in the vacuum; taking out the monolithic honeycomb carrier from the hermetic container to place the monolithic honeycomb carrier on a recess container having an elastic sealing ring; removing the excess coating slurry in the channels in the monolithic honeycomb carrier from the bottom of the monolithic honeycomb carrier by vacuum extraction; and collecting the excess coating slurry removed by vacuum extraction for being reused; and obtaining the monolithic honeycomb carrier applied with the washcoat after drying and calcination.