The disclosure is directed to an exhaust gas heating unit for an exhaust gas system of an internal combustion engine. The exhaust gas heating unit includes at least one electrically conductive heating conductor element, wherein the at least one electrically conductive heating conductor element is configured from bent flat strip material. The exhaust gas system conducts exhaust gas defining an exhaust gas primary flow direction (H). The heating conductor element can have a plurality of broad sides arranged to be substantially parallel to the exhaust gas primary flow direction (H) and a plurality of end faces arranged substantially orthogonally to the exhaust gas primary flow direction (H).

A lean NO.sub.x trap composition for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC), and carbon monoxide (CO), and the trapping and reduction of nitrogen oxides (NO.sub.x) is disclosed. The lean NO.sub.x trap composition can have a washcoat layer on a carrier substrate including a first support material comprising greater than 50% by weight of a reducible metal oxide; 10 to 30% by weight of alkaline earth metal supported on a second support material comprising a refractory metal oxide and 50% or less by weight of a reducible metal oxide and; and a platinum group metal component supported on at least one of the first support material and/or the second support material. A portion of the first support material may further include 0.5% to 10% by weight of an alkaline earth metal.

A catalyst powder according to the present invention is a catalyst powder that includes: a core portion that contains ceria and zirconia; and a surface layer portion that is located on the core portion and contains ceria and zirconia. The ratio (M.sub.2/M.sub.1) is 0.30 or more and 0.95 or less, the ratio (M.sub.2/M.sub.1) being the ratio of a mole fraction M.sub.2 (mol %) of cerium in the surface layer portion measured using X-ray photoelectron spectroscopy to a mole fraction M.sub.1 (mol %) of cerium in the entire powder. It is preferable that the ratio (M.sub.4/2/M.sub.3/1) between M.sub.3/1 and M.sub.4/2 is 1.1 or more and 5.0 or less, wherein M.sub.3/1 (=M.sub.3/M.sub.1) represents the ratio between a mole fraction M.sub.3 (mol %) of zirconium in the entire powder and a mole fraction M.sub.1 (mol %) of cerium in the entirety of the powder, and M.sub.4/2 (=M.sub.4/M.sub.2) represents the ratio between a mole fraction M.sub.4 (mol %) of zirconium measured using X-ray photoelectron spectroscopy and a mole fraction M.sub.2 (mol %) of cerium measured using X-ray photoelectron spectroscopy.

An oxygen storage material comprises three pyrochlore-type composite oxides which are a ceria-zirconia composite oxide, a lanthana-zirconia composite oxide, and a ceria-zirconia-lanthana composite oxide, and which coexist together, wherein the oxygen storage material contains: first secondary particles made of the pyrochlore-type ceria-zirconia composite oxide and the pyrochlore-type ceria-zirconia-lanthana composite oxide; and second secondary particles made of the pyrochlore-type lanthana-zirconia composite oxide and the pyrochlore-type ceria-zirconia-lanthana composite oxide.

A NO.sub.x absorber catalyst for treating an exhaust gas from a lean burn engine. The NO.sub.x absorber catalyst comprises a molecular sieve catalyst comprising a noble metal and a molecular sieve, wherein the molecular sieve contains the noble metal; an oxygen storage material for protecting the molecular sieve catalyst; and a substrate having an inlet end and an outlet end.

A porous ceramic honeycomb body including a substrate of intersecting porous walls forming axial channels extending from a first end face to a second end face. An active portion of the walls include a zeolite catalyst disposed inside pores thereof and/or is comprised of an extruded zeolite and a three way catalyst (TWC) is disposed on wall surfaces of at least a portion of the active portion.

A catalyzed substrate monolith 12 for use in treating exhaust gas emitted from a lean-burn internal combustion engine, which catalyzed substrate monolith 12 comprising a first washcoat coating 16 and a second washcoat coating 18, wherein the first washcoat coating comprises a catalyst composition comprising at least one platinum group metal (PGM) and at least one support material for the at least one PGM, wherein at least one PGM in the first washcoat coating is liable to volatilize when the first washcoat coating is exposed to relatively extreme conditions including relatively high temperatures, wherein the second washcoat coating comprises at least one metal oxide for trapping volatilized PGM and wherein the second washcoat coating is oriented to contact exhaust gas that has contacted the first washcoat coating.

The present invention provides an oxidation catalyst composition suitable for at least partial conversion of gaseous hydrocarbon emissions, e.g., methane. The oxidation catalyst composition includes at least one platinum group metal (PGM) component supported onto a porous zirconia-containing material that provides an effect on hydrocarbon conversion activity. The porous zirconia-containing material is at least 90% by weight in the monoclinic phase. Furthermore, the PGM component can comprise at least one platinum group metal in the form of colloidally deposited nanoparticles. The oxidation catalyst composition can be used in the treatment of emissions from lean compressed natural gas engines.

A composition of zirconium oxide and at least one oxide of a rare earth other than cerium is described. The zirconium oxide has a weight proportion of at least 50% and, after calcination at a temperature of 900? C. for 4 hours, the composition exhibits two populations of pores of which their respective diameters are centered. The diameter of the first pore has a value of from 20 nm to 40 nm and in the second pore has a value of from 80 nm to 200 nm. Further described is how the composition can be used for treating the exhaust gases of internal combustion engines.

Extruded honeycomb catalyst bodies and methods of manufacturing same. The catalyst body includes a first oxide selected from the group consisting of tungsten oxides, vanadium oxides, and combinations thereof, a second oxide selected from the group consisting of cerium oxides, lanthanum oxides, zirconium oxides, and combinations thereof, and a zeolite.