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.

A layered diesel oxidation catalyst for treatment of exhaust gas emissions from a diesel engine comprising: a flow-through monolith substrate having a honeycomb structure and comprising a front zone and a rear zone, wherein the front zone of the substrate comprises a combination of layers, one on top of another and comprising two or more of layers A, B and C; and the rear zone comprises Layer D, wherein: Layer A comprises platinum, palladium, or combinations thereof on a molecular sieve; Layer B comprises 1) platinum, palladium, or combinations thereof on a refractory metal oxide support; and 2) an alkaline earth metal, preferably barium, strontium or combinations thereof; Layer C comprises 1) a platinum group metal, which is platinum or a combination of both platinum and palladium on a refractory metal oxide support; and 2) a promoter metal, which is manganese and/or bismuth; and layer D comprises 1) platinum or a combination of both platinum and palladium on a refractory metal oxide support; and 2) manganese (Mn).

A particulate filter disclosed herein includes a wall-flow structure substrate 10 and a wash coat layer 20 held inside a partition 16 of the substrate 10. The wash coat layer 20 includes an inlet layer 22 formed to have predetermined length L.sub.A and thickness T.sub.A from near an end thereof on an exhaust gas inflow side X1, and an outlet layer 24 formed to have predetermined length L.sub.B and thickness T.sub.B from near an end thereof on an exhaust gas outflow side X2. The inlet layer 22 and the outlet layer 24 partially overlap each other. In the particulate filter disclosed herein, the inlet layer 22 contains a precious metal catalyst, while the outlet layer 24 contains substantially no precious metal catalyst. The length L.sub.A of the inlet layer is 50% or more and 75% or less of a total length L of the partition 16. Thus, the particulate filter is capable of achieving both PM collection performance and pressure-drop reduction performance at high levels.

Provide is a functional structural body that can suppress aggregation of metal oxide nanoparticles and prevent functional loss of metal oxide nanoparticles, and thus exhibit a stable function over a long period of time. A functional structural body (1) includes: a skeletal body (10) of a porous structure composed of a zeolite-type compound; and at least one type of metal oxide nanoparticles (20) containing a perovskite-type oxide present in the skeletal body (10), the skeletal body (10) having channels (11) that connect with each other, and the metal oxide nanoparticles (20) being present at least in the channels (11) of the skeletal body (10).

A functional structural body includes a skeletal body of a porous structure composed of a zeolite-type compound, and at least one type of metallic nanoparticles present in the skeletal body, the skeletal body having channels connecting with each other, the metallic nanoparticles being present at least in the channels of the skeletal body.

The presently invention provides an emission control catalyst article comprising a substrate, a bottom washcoat layer comprising a platinum group metal coated on the 60 to 100% length of the substrate, and a top washcoat layer comprising a platinum group metal coated on the 60 to 100% length of the substrate such that the top coat covers at least 60% of the length of the bottom washcoat layer, wherein at least a portion of the top washcoat layer, the bottom washcoat layer or both washcoat layers comprises a platinum group metal deposited within the said washcoat layer(s) with a platinum group metal gradient such that the PGM concentration in a top-most portion of the said washcoat layer is at least two time higher compared to the PGM concentration in a bottom-most portion of the said washcoat layer.

A method of manufacturing a catalyst article, the method comprising: providing a slurry comprising a support material, palladium ions, alkaline-earth-metal ions and an organic compound, wherein the organic compound comprises a functional group selected from a sulfo group (—SO.sub.3H), a sulfonyl group (—S(═O).sub.2—) and a sulfinyl group (—S(═O)—); disposing the slurry on a substrate; and heating the slurry to form nanoparticles of the palladium and nanoparticles of a sulfate of the alkaline earth metal on the support material.

A three-way catalyst article with improved ammonia emission control, and its use in an exhaust system for gasoline engines, is disclosed. The catalyst article for treating exhaust gas from a gasoline engine comprising: a substrate comprising an inlet end, an outlet end with an axial length L; a first catalytic region beginning at the inlet end, wherein the first catalytic region comprises a first zeolite; and a second catalytic region beginning at the outlet end, wherein the second catalytic region comprises a second platinum group metal (PGM) component, a second oxygen storage capacity (OSC) material, and a second inorganic oxide; wherein the second PGM component is selected from the group consisting of palladium, platinum, rhodium and a combination thereof.

A supported catalyst for decomposing an organic substance that includes a support and a catalyst particle supported on the support. The catalyst particle contains a perovskite-type composite oxide represented by A.sub.xB.sub.yM.sub.zO.sub.w, where the A contains at least one selected from Ba and Sr, the B contains Zr, the M is at least one selected from Mn, Co, Ni and Fe, y+z=1, x≥0.995, z≤0.4, and w is a positive value satisfying electrical neutrality. A film thickness of a catalyst-supporting film supported on the support and containing the catalyst particle is 5 μm or more, or a supported amount as determined by normalizing a mass of the catalyst particle supported on the support by a volume of the support is 45 g/L or more.

The present invention relates to a catalyst comprising two layers on an inert catalyst carrier, wherein a layer A lying directly on the catalyst carrier contains at least one platinum group metal and one cerium/zirconium/SE mixed oxide, and a layer B, applied on layer A and in direct contact with the flow of exhaust gas, contains at least one platinum group metal and a cerium/zirconium/SE mixed oxide, wherein SE stands for a rare earth metal other than from cerium, characterized in that the fraction of SE oxide in the cerium/zirconium/SE mixed oxide of layer A is less than the fraction of SE oxide in the cerium/zirconium/SE mixed oxide of layer B.