Particulate filter with low soot loaded coating

摘要

A ceramic particulate filter having a porous catalytic material deposited on walls within the filter. Particulate matter is trapped in the walls of the filter and the catalytic material removes gases, such as nitrogen oxides (NOx), from gases passing through the filter. The filter, in one embodiment, is adaptable for use with internal combustion (gas and diesel) engines. A method of making the filter is also described.

主权项

1. A ceramic particulate filter for internal combustion engines, the ceramic particulate filter comprising:
a. a ceramic body comprising a plurality of inlet channels, a plurality of outlet channels, and a plurality of porous walls separating the inlet channels from adjacent outlet channels, wherein each of the porous walls has a continuous porous structure capable of trapping particulate matter; and b. a first porous catalytic coating comprising a first catalytic material and a porous support material, wherein the first catalytic material is incorporated within the porous support material, wherein the first porous catalytic coating is not deposited within the porous walls, and wherein each of the inlet channels is in fluid communication with at least one of the outlet channels through the first catalytic coating and the porous wall separating the inlet channel from the outlet channel; and c. a second porous catalytic coating deposited on the outer surfaces of the porous wall in the outlet channel, wherein the second porous catalytic coating is not deposited within the porous walls, wherein the second porous catalytic coating comprises a second catalytic material that differs from the first catalytic material, and wherein the first porous catalytic coating is deposited on top of the second porous catalytic coating in the outlet channel.