A diesel-emissions reduction unit having an inlet adapted to receive an exhaust stream of the diesel engine; a diesel oxidation trap catalyst located adjacent the inlet; a dosing controller and an injection lance arranged to meter aqueous NH.sub.3 into the exhaust stream; a NOx concentration sensor and a NH.sub.3 concentration sensor with at least one oxidation catalyst panel arranged to isolate the NOx concentration sensor from NH.sub.3 in the exhaust stream; and an exhaust heater arranged to heat the exhaust stream of the diesel engine toward the inlet of the diesel emissions reduction unit.

A pillar shaped honeycomb structure includes: a porous partition wall that defines a plurality of cells, the cells forming flow paths for a fluid, the cells extending from an inflow end face to an outflow end face; and an outer peripheral wall located at the outermost circumference. At least a part of surfaces of the partition walls has a surface layer, and the surface layer includes magnetic particles and has permeability.

When the porous ceramic structure contains Co together with Fe or Mn, the Co content is higher than or equal to 0.1 mass % and lower than or equal to 3.0 mass % in terms of Co.sub.3O.sub.4, and when the porous ceramic structure contains Co without containing Fe and Mn, the Co content is higher than or equal to 0.2 mass % and lower than or equal to 6.0 mass % in terms of Co.sub.3O.sub.4. The ratio of the sum of the Fe content in terms of Fe.sub.2O.sub.3, the Mn content in terms of Mn.sub.2O.sub.3, and the Co content in terms of Co.sub.3O.sub.4 to the Ce content in terms of CeO.sub.2 is higher than or equal to 0.8 and lower than or equal to 9.5.

The invention relates to a wall-flow filter as a particle filter with catalytically active coatings in the channels which are closed in a gas-tight manner at the opposing closed ends of the channels A at the first end, wherein the inlet region of the filter is additionally supplied with a dry powder-gas aerosol which contains metal compounds with a high melting point (such as the metal oxides Al203, Si02, Fe02, Ti02, Zn02, etc. for example) and which is to simultaneously improve the catalytic activity and the degree of filtration efficiency with respect to the exhaust gas back-pressure.

Provided herein is a catalytic article including a catalytic coating disposed on a substrate, wherein the catalytic coating comprises a bottom coating on the substrate and a top coating layer on the bottom coating layer, one such coating layer containing a platinum group metal on a refractory metal oxide support and the other such coating layer containing a ceria-containing molecular sieve. Such catalytic articles are effective toward treating exhaust gas streams of internal combustion engines and exhibit outstanding resistance to sulfur.

An exhaust aftertreatment system includes a cross-flow selective catalytic reduction catalyst. The cross-flow selective catalytic reduction catalyst includes a housing and a substrate assembly. The substrate assembly includes a plurality of first substrate layers defining a plurality of first flow channels and a plurality of second substrate layers defining a plurality of second flow channels. The exhaust aftertreatment system includes a passive NO.sub.x adsorber. The passive NO.sub.x adsorber includes a housing. The housing includes an inlet in exhaust gas receiving communication with the plurality of first flow channels of the cross-flow selective catalytic reduction catalyst. The housing includes an outlet in exhaust gas providing communication with the plurality of second flow channels of the cross-flow selective catalytic reduction catalyst. The passive NO.sub.x adsorber includes a substrate positioned in the housing. The substrate includes a passive NO.sub.x adsorber washcoat.

An exhaust aftertreatment system includes a cross-flow selective catalytic reduction catalyst. The cross-flow selective catalytic reduction catalyst includes a housing and a substrate assembly. The substrate assembly includes a plurality of first substrate layers defining a plurality of first flow channels and a plurality of second substrate layers defining a plurality of second flow channels. The exhaust aftertreatment system includes a passive NO.sub.x adsorber. The passive NO.sub.x adsorber includes a housing. The housing includes an inlet in exhaust gas receiving communication with the plurality of first flow channels of the cross-flow selective catalytic reduction catalyst. The housing includes an outlet in exhaust gas providing communication with the plurality of second flow channels of the cross-flow selective catalytic reduction catalyst. The passive NO.sub.x adsorber includes a substrate positioned in the housing. The substrate includes a passive NO.sub.x adsorber washcoat.

A bottom face processing method of a pillar-shaped honeycomb structure including steps of: preparing a pillar-shaped honeycomb structure including a plurality of first cells which extend in parallel with each other from a first bottom face to a second bottom face, and each of which is opened in the first bottom face and has a protruding plugged portion in the second bottom face, and a plurality of second cells each of which is adjacent to at least one of the first cells with a partition wall interposed therebetween, which extend in parallel with each other from the first bottom face to the second bottom face, and each of which has a protruding plugged portion in the first bottom face, and is opened in the second bottom face; and removing the protruding portion from the plugged portion of each of the first cells and the second cells of the pillar-shaped honeycomb structure.

A particle filter assembly for a motor vehicle includes a particle filter, an exhaust-gas-conducting line which opens into the particle filter, and a secondary air supply. The secondary air supply is formed separately from the exhaust-gas-conducting line and fresh air is suppliable to the particle filter via the secondary air supply.

A secondary air system for an aircraft engine comprises an air flow path communicating between a source of pressurized cooling air and an air consuming component. A filter is disposed in the air flow path upstream from the air consuming component. The filter has at least one of: openings of a size selected for capturing suspended particles; and a filter surface material for binding with chemical contaminants.