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).

Described are three-way conversion (TWC) catalytic articles effective to abate hydrocarbons (HCs), carbon monoxide (CO), and nitrogen oxides (NO.sub.x) from an engine exhaust gas containing phosphorous impurities. The disclosed catalytic article has a layered catalytic material, wherein the first layer of the catalytic material is disposed directly on the substrate and a second layer is disposed on top of the first layer. The second layer includes phosphorus resistant materials that prevent catalytic poisoning of the catalytic article by the phosphorous impurities. In particular, the second layer includes a phosphorus trap material having an alkaline earth metal component and a rhodium component impregnated on a phosphorus-resistant support material.

Provided is a catalyst for exhaust gas purification, the catalyst comprising: a noble metal; an alumina support particle; and a ZrO.sub.2 semiconductor support particle deposited on a surface of the alumina support particle.

Provided is an exhaust gas purification catalyst capable of reducing a noble metal amount while maintaining a catalyst performance, which comprises a substrate and at least three catalyst coating layers formed on the substrate, the first and third catalyst coating layers contain Pd as a catalyst metal and are formed in a range of a predetermined length from an upstream end surface in an exhaust gas flow direction, and the second catalyst coating layer contains Rh as a catalyst metal and is formed in a range of a predetermined length from a downstream end surface in the exhaust gas flow direction.

The present invention relates to a catalyst, in particular to a three-way diesel catalyst, for the treatment of a diesel exhaust gas, the catalyst comprising a substrate and two specific coatings disposed thereon, wherein the first coating particularly comprises a first platinum group metal component supported on a first oxidic support material, a second platinum group metal component supported on a second oxidic support material, and a first oxygen storage component, wherein at least 30 weight-% of the first oxygen storage component consist of cerium oxide, calculated as CeOa, and wherein the second coating particularly comprises a third platinum group metal component and a fourth platinum group metal component, wherein the third platinum group metal component and the fourth platinum group metal component are supported on a third oxidic support material. Further, a process for the preparation of such a catalyst is disclosed as well as a use thereof.

The present invention provides a particulate filter for use in an emission treatment system of a gasoline engine, the filter having an inlet side and an outlet side, wherein at least the inlet side is loaded with a synthetic ash.

A nitrogen oxide storage material comprising: Mg.sub.1−yAl.sub.2O.sub.4−y, wherein y is a number satisfying 0≤y≤0.2, a noble metal, an oxide of a metal other than the noble metal, and a barium compound, the noble metal, the oxide, and the barium compound being loaded on Mg.sub.1−yAl.sub.2O.sub.4−y. The metal oxide comprises at least one metal oxide selected from zirconium oxide, praseodymium oxide, niobium oxide, and iron oxide.

An exhaust gas purification catalyst including an alkaline-earth metal carried on a porous carrier in a highly dispersed state. The catalyst layer of the exhaust gas purification catalyst has an alkaline-earth metal carrying region including a porous carrier, Pt, and a sulfuric acid salt of at least one alkaline-earth metal carried on the porous carrier, wherein a value of R.sub.Ae/Pt is 0.5 or more, where R.sub.Ae/Pt represents the Pearson's correlation coefficient calculated using α and β in each pixel obtained by, for a cross section of the region, performing the area analysis by FE-EPMA under the conditions of: pixel size 0.34 μm×0.34 μm; and number of measured pixels 256×256; and measuring an intensity (α: cps) of a characteristic X ray of an element (Ae) of the alkaline-earth metal and an intensity (β: cps) of a characteristic X ray of Pt for each pixel.

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.