Patent ID: 8122603

Claim:
A method for disposing a selective catalytic reduction (SCR) catalyst composition on a wall flow monolith, wherein the wall flow monolith has a plurality of longitudinally extending passages formed by longitudinally extending walls bounding and defining said passages, wherein the passages comprise inlet passages having an open inlet end and a closed outlet end, and outlet passages having a closed inlet end and an open outlet end, the method comprising: immersing the wall flow monolith in an aqueous slurry comprising the SCR catalyst composition from a first direction to deposit the SCR catalyst composition on the inlet passages; removing excess slurry from the inlet passages by forcing a compressed gas stream through the outlet passages and applying a vacuum to the inlet passages; immersing the wall flow monolith in an aqueous slurry comprising the SCR catalyst composition from a second direction, opposite the first direction, to deposit the SCR catalyst composition on the outlet passages; removing excess slurry from the outlet passages by forcing a compressed gas stream through the inlet passages and applying a vacuum to the outlet passages; and drying and calcining the coated wall flow monolith.