Provided are multi-zone catalyst articles, methods of manufacturing multi-zone catalyst articles, and methods for controlling emissions in diesel engine exhaust streams with multi-zone catalyst articles, where the emission treatment system of various embodiments effectively treats diesel engine exhaust with a single multi-zone catalyst article.

This disclosure is directed to catalyst compositions, catalytic articles for purifying exhaust gas emissions and methods of making and using the same. In particular, the disclosure relates to a catalytic article including a catalytic material on a substrate, wherein the catalytic material has a first layer and a second layer. The first layer provides effective lean NO.sub.x trap functionality and the second layer provides effective three-way conversion of carbon monoxide, hydrocarbons, and nitrogen oxides (NO.sub.x).

An exhaust gas cleaning catalyst is provided with a fire-resistant three-dimensional structural body, a first catalyst layer provide on a first surface side of the fire-resistant three-dimensional structural body, and a second catalyst layer provided on a side of the first catalyst layer opposite to the fire-resistant three-dimensional structural body. The first catalyst layer contains: a complex oxide including cerium and zirconium; and elemental rhodium. The second catalyst layer contains: a complex oxide including cerium and zirconium; and elemental palladium. The amount of cerium included in the second catalyst layer, in terms of cerium dioxide, is 10-25 g per liter of the fire-resistant three-dimensional structural body.

Sulfur-resistant synergized platinum group metals (SPGM) catalysts with significant oxidation capabilities are disclosed. Catalytic layers of SPGM catalyst samples are prepared using conventional synthesis techniques to build a washcoat layer completely or substantially free of PGM material. The SPGM catalyst includes a washcoat layer comprising YMn.sub.2O.sub.5 (pseudobrookite) and an overcoat layer including a Pt/Pd composition with total PGM loading of at or below 5.0 g/ft.sup.3. Resistance to sulfur poisoning and catalytic stability is observed under 5.2 gS/L condition to assess significant improvements in NO oxidation, and HC and CO conversions.

The present disclosure relates to copper-containing molecular sieve catalysts that are highly suitable for the treatment of exhaust containing NOx pollutants. The copper-containing molecular sieve catalysts contain ion-exchanged copper as Cu.sup.+2 and Cu(OH).sup.+1, and DRIFT spectroscopy of the catalyst exhibits perturbed T-O-T vibrational peaks corresponding to the Cu.sup.+2 and Cu(OH).sup.+1. In spectra taken of the catalytic materials, a ratio of the Cu.sup.+2 to the Cu(OH).sup.+1 peak integration areas preferably can be ≥1. The copper-containing molecular sieve catalysts are aging stable such that the peak integration area percentage of the Cu.sup.+2 peak (area Cu.sup.+2/(area Cu.sup.+2+area Cu(OH).sup.+1)) increases by ≤20% upon aging at 800° C. for 16 hours in the presence of 10% H.sub.2O/air, compared to the fresh state.

A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprising: a substrate comprising an inlet end and an outlet end with an axial length L; a first catalytic region comprising a first platinum group metal (PGM) component and a first PGM support material, wherein the first catalytic region comprises up to 5 wt. % Sn.

The invention relates to a catalytic article comprising a substrate having an inlet and an outlet; a first coating comprising a blend of: (1) platinum on a support, and (2) a first SCR catalyst comprising a Cu- and Mn-exchanged molecular sieve; and a second coating comprising a second SCR catalyst; wherein the support comprises at least one of a zeolite or a SiO.sub.2-Al.sub.2O.sub.3 mixed oxide. The platinum may be fixed on the support in solution.

A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprising: a substrate comprising an inlet end, an outlet end with an axial length L; an inlet catalyst layer beginning at the inlet end and extending for less than the axial length L, wherein the inlet catalyst layer comprises an inlet palladium component; an outlet catalyst layer beginning at the outlet end and extending for less than the axial length L, wherein the outlet catalyst layer comprises an outlet rhodium component; and wherein the outlet catalyst layer overlaps with the inlet catalyst layer.

A phosphorus compound-containing exhaust gas purifying catalyst includes: a refractory three-dimensional structure extending from a gas inflow side end surface to a gas outflow side end surface, the refractory three-dimensional structure having cell walls that define and form multiple gas flow paths, the gas flow paths running from the gas inflow side end surface to the gas outflow side end surface; a lower catalyst layer that contains Pd and is formed continuously from the gas inflow side end surface on the cell walls; a gas inflow side upper catalyst layer that contains Rh and is located as an uppermost layer on the cell walls; and a gas outflow side upper catalyst layer that contains Rh and is located as an uppermost layer on the cell walls.

The invention relates to a catalyst which comprises a carrier substrate, palladium, and a zeolite, the largest channels of which are formed by 10 tetradrically coordinated atoms; to the use of said catalyst as a passive nitrogen oxide adsorber, an exhaust gas system which contains said catalyst and an SCR catalyst, and to a method for purifying the exhaust gas of motor vehicles using said exhaust gas system.