Catalysts including multi-transition metal doped copper-cobalt spinel mixed oxide catalyst materials for direct NO.sub.x decomposition with selectivity to N.sub.2 from combustion engine exhaust, while minimizing formation of the N.sub.2O product. In one example, the catalyst may include a ternary zinc-doped copper-cobalt spinel material or a quaternary manganese+zinc doped copper-cobalt spinel material. The catalysts are effective for reducing NO to N.sub.2 at suitable temperatures of 350-500° C., with and without excess O.sub.2 presence.

Catalysts including multi-transition metal doped copper-cobalt spinel mixed oxide catalyst materials for direct NO.sub.x decomposition with selectivity to N.sub.2 from combustion engine exhaust, while minimizing formation of the N.sub.2O product. In one example, the catalyst may include a ternary zinc-doped copper-cobalt spinel material or a quaternary manganese+zinc doped copper-cobalt spinel material. The catalysts are effective for reducing NO to N.sub.2 at suitable temperatures of 350-500° C., with and without excess O.sub.2 presence.

A device that includes a conduit, a first window, a second window, a first catalyzed layer, a second catalyzed layer, an optical source, and an optical detector is disclosed. The conduit may be configured to receive an exhaust gas. The first catalyzed layer may be disposed on the first window and the second catalyzed layer may be disposed on the second window. The first catalyzed layer and the second catalyzed layer may be configured to cause a reaction with soot in the exhaust gas at an activation temperature to reduce accumulation of the soot on the first window and the second window. The optical source may be configured to emit a beam of light into the conduit through the first window. The optical detector may be configured to receive at least a portion of the beam of light through the second window.

A lean NO.sub.x trap catalyst and its use in an emission treatment system for internal combustion engines is disclosed. The lean NO.sub.x trap catalyst comprises a first layer, a second layer, and a third layer.

A process for manufacturing an exhaust system for an internal combustion engine includes the steps: a) providing at least one exhaust gas-carrying component (12, 18) for the exhaust system (10); b) applying a basic material layer (24, 26) to at least one area of a surface of at least one of the exhaust gas-carrying components (12, 16) in a high-temperature application process; and c) applying a catalytically active material layer (28, 30) to the basic material layer (24, 26) in a low-temperature application process.

A vehicular exhaust filter (2) comprising a porous substrate having an inlet face and an outlet face with the porous substrate comprising inlet channels extending from the inlet face and outlet channels extending from the outlet face is disclosed. The inlet channels and the outlet channels are separated by a plurality of filter walls having a porous structure.

The vehicular exhaust filter (2) is loaded with a refractory powder having a tapped density before loading of less than 0.10 g/cm.sup.3 and the vehicular exhaust filter has a mass loading of the refractory powder of less than 10 g/l.

An oxidation catalyst includes cerium dioxide particles and a metal oxide. The cerium dioxide particles contain an ancillary component that is at least one of lanthanum, aluminum, and iron. The metal oxide contains iron and manganese and is held by the cerium dioxide particles.

A substrate for a catalytic converter, comprising an open cell carbon foam having a geometric surface area of at least about 5000 m.sup.2/m.sup.3 and a permeability of at least about 8.0 darcys.

A catalytic article for treating exhaust gas comprising: a first catalytic region beginning at the inlet end and extending for less than the axial length L, wherein the first catalytic region comprises a first palladium component and a first oxygen storage capacity (OSC) material comprising ceria; a second catalytic region beginning at the outlet end and extending for less than the axial length L, wherein the second catalytic region comprises a second palladium component and a second OSC material comprising ceria; a third catalytic region beginning at the outlet end and extending for less than the axial length L, wherein the third catalytic region comprises a third rhodium component and a third OSC material comprising ceria; wherein at least a portion of the first catalytic region is not covered by the second catalytic region and/or the third catalytic region;

and wherein (a) the ceria amount in the first catalytic region is less than 50% of the total ceria amount in the first, second, and third catalytic regions; or (b) the ceria loading in the first catalytic region is less than 50% of the sum of the ceria loading in the first, second, and third catalytic regions.

A substrate for a catalytic converter, comprising an open cell carbon foam having a geometric surface area of at least about 5000 m.sup.2/m.sup.3 and a permeability of at least about 8.0 darcys.