Patent ID: 8491966

Claim:
A process for introducing a catalytic coating into the pores of a ceramic flow-through honeycomb body through which parallel flow channels which are separated from one another by channel walls having an open pore structure run between two end faces, with coating being carried out using a catalyst suspension comprising solids suspended in a carrier liquid, which comprises a) contacting the two end faces of the honeycomb body with in each case a perforated mask having a plurality of open and closed regions, with the perforated masks being arranged so that the plurality of open regions of the perforated mask on the one end face are opposite the closed regions of the perforated mask on the other end face, wherein the area of each open and closed region covers a plurality of flow channels, the plurality of open regions have a grid spacing, and the cross-sectional areas of the open regions of both perforated masks are different, b) introducing the catalyst suspension through the perforated mask on the one end face of the honeycomb body until the suspension exits through the perforated mask on the other end face which thereby forces the catalyst suspension to flow through and coat the open pore structure of the channel walls, c) blowing-out or sucking-out any excess catalyst suspension, d) releasing the contact with the perforated masks, and e) calcining the coated honeycomb body to give the ceramic flow-through honeycomb body having the catalytic coating.