Abstract: The present invention relates to a diesel oxidation catalyst comprising a carrier substrate, and a first washcoat layer disposed on the substrate, the first washcoat layer comprising palladium supported on a support material comprising a metal oxide, gold supported on a support material comprising a metal oxide, and a ceria comprising compound, as well as a process for the preparation of such catalyst.

Abstract: An exhaust system for a compression ignition engine comprising an oxidation catalyst for treating carbon monoxide (CO) and hydrocarbons (HCs) in exhaust gas from the compression ignition engine, wherein the oxidation catalyst comprises: a platinum group metal (PGM) component selected from the group consisting of a platinum (Pt) component, a palladium (Pd) component and a combination thereof; an alkaline earth metal component; a support material comprising a modified alumina incorporating a heteroatom component; and a substrate, wherein the platinum group metal (PGM) component, the alkaline earth metal component and the support material are disposed on the substrate.

Abstract: Described are SCR catalyst systems comprising a first SCR catalyst composition and a second SCR catalyst composition arranged in the system, the first SCR catalyst composition promoting higher N2 formation and lower N2O formation than the second SCR catalyst composition, and the second SCR catalyst composition having a different composition than the first SCR catalyst composition, the second SCR catalyst composition promoting lower N2 formation and higher N2O formation than the first SCR catalyst composition. The SCR catalyst systems are useful in methods and systems to catalyze the reduction of nitrogen oxides in the presence of a reductant.

Abstract: An ammonia oxidation catalyst being superior in heat resistance and capable of suppressing by-production of N2O or NOx. The ammonia oxidation catalyst is made by coating at least two catalyst layers having a catalyst layer (lower layer) including a catalyst supported a noble metal on an inorganic base material including any of a composite oxide (A) having at least titania and silica as main components, alumina, and a composite oxide (B) consisting of alumina and silica; and a catalyst layer (upper layer) including a composite oxide (C) consisting of at least silica, tungsten oxide, ceria and zirconia, at the surface of an integral structure-type substrate, wherein a composition of the composite oxide (C) is silica: 20% by weight or less, tungsten oxide: 1 to 50% by weight, ceria: 1 to 60% by weight, and zirconia: 30 to 90% by weight.

Abstract: A treatment device configured to receive a flow of exhaust from a power source is disclosed. The treatment device may have a first layer, a second layer, and a substrate layer. The first layer may include a selective catalytic reduction layer, and the second layer may be disposed downstream of the first layer and include an oxidation catalyst support. The substrate layer may be disposed adjacent to the second layer. Additionally, an additive may be disposed downstream of the first layer. The additive may be operative to substantially prohibit migration of a component of the second layer to the first layer upon treatment of the flow of exhaust by the oxidation catalyst support.

Abstract: Disclosed herein is a layered three-way catalytic system being separated in a front and a rear portion having the capability of simultaneously catalyzing the oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides. Provided is a catalyst composite comprising a single front catalytic layer and two rear catalytic layers in conjunction with a substrate, where the single font layer and the rear bottom layer comprise a Pd component, the rear top layer comprises a Rh component, and the rear bottom layer is substantially free of an oxygen storage component (OSC).

Abstract: Disclosed is a gas purifying catalyst for an internal combustion engine comprising: a carrier and a catalyst layer formed on the carrier, the catalyst layer including a first catalyst, a second catalyst and a third catalyst. The first catalyst comprises Pd supported in a first support, the first support comprising alumina. The second catalyst comprises Rh supported in a second support, the second support comprising a complex oxide of ceria-zirconia. The third catalyst comprising Pd supported in a third support, the third support comprising a complex oxide of ceria-zirconia.

Abstract: An exhaust emission control catalyst disclosed herein is equipped with a rhodium catalytic layer and a platinum catalytic layer, and is characterized in that a relationship between a mole average (X) of a Pauling's electronegativity that is calculated as to elements included in the rhodium catalytic layer except platinum group elements and oxygen and a mole average (Y) of a Pauling's electronegativity that is calculated as to elements included in the platinum catalytic layer except platinum group elements and oxygen is 1.30?X?1.45 and 1.47?Y?2.0. According to this exhaust emission control catalyst, an interlayer transfer of platinum and/or rhodium and the alloying of platinum and/or rhodium are suppressed during use of the catalyst, and high exhaust gas purification performance can be exerted.

Abstract: A catalytically active particulate filter is proposed which is suitable for use in an exhaust gas cleaning system for diesel engines. The particulate filter removes diesel soot particles from the exhaust gas and is also effective to oxidize carbon monoxide and hydrocarbons and to convert nitrogen monoxide at least proportionally into nitrogen dioxide. The particulate filter comprises a filter body (3) and two catalytically active coatings (1) and (2) which contain platinum and palladium, or platinum or palladium respectively, wherein the platinum content of the second catalytically active coating (2) is higher than the platinum content of the first catalytically active coating (1).

Abstract: An exhaust gas-purifying catalyst includes a support provided with one or more through-holes through which exhaust gas flows, and a catalytic layer supported by the support and containing an oxygen storage material. The exhaust gas-purifying catalyst includes a first section to which the exhaust gas is supplied, and a second section to which the exhaust gas having passed through the first section is supplied. The catalytic layer includes a layered structure of a first catalytic layer containing platinum and/or palladium and a second catalytic layer containing rhodium in the first catalytic section and further includes a third layer containing rhodium in the second section. The second section is smaller in oxygen storage material content per unit volumetric capacity than the first section.

Abstract: The present invention relates to a catalyst composition comprising a carrier substrate, a layer (i) coated on said carrier substrate comprising at least one precious group metal, a layer (ii) comprising Rh, and a layer (iii) comprising Pd and/or Pt and being substantially free of Ce, Ba and Rh, wherein the layer (iii) has a lower weight than the layer (i) or the layer (ii). Furthermore, the present invention relates to a method for treating an exhaust gas stream using said catalyst composition.

Abstract: Ammonia oxidation catalyst being superior in heat resistance and capable of suppressing by-production of N2O and leakage of ammonia. The ammonia oxidation catalyst (AMOX) removes surplus ammonia, in selectively reducing nitrogen oxides by adding urea or ammonia and using a selective catalytic reduction (SCR) catalyst, into exhaust gas, wherein the ammonia oxidation catalyst is made by coating at least two catalyst layers having a catalyst layer (lower layer) including a catalyst supported a noble metal element on a composite oxide (A) having titania and silica as main components, and a catalyst layer (upper layer) including a composite oxide (C) consisting of tungsten oxide, ceria, and zirconia, at the surface of an integral structure-type substrate, wherein a composition of the composite oxide (C) is tungsten oxide: 1 to 50% by weight, ceria: 1 to 60% by weight, and zirconia: 30 to 90% by weight.

Abstract: Described is a catalyzed soot filter wherein the inlet coating of the filter comprises an oxidation catalyst comprising platinum (Pt) and optionally palladium (Pd), wherein the outlet coating of the filter comprises an oxidation catalyst comprising Pd and optionally Pt, wherein the Pt concentration in the outlet coating is lower than the Pt concentration in the inlet coating and wherein the weight ratio of Pt:Pd in the outlet coating is in the range of from 0:1 to 2:1; and wherein the inlet coating and the outlet coating are present on the wall flow substrate at a coating loading ratio in the range of from 0.5 to 1.5, calculated as ratio of the loading of the inlet coating (in g/inch3 (g/(2.54 cm)3)):loading of the outlet coating (in g/inch3 (g/(2.54 cm)3)). Systems include such catalyzed soot filters, methods of diesel engine exhaust gas treatment and methods of manufacturing catalyzed soot filters are also described.

Abstract: An exhaust gas purification catalyst has a substrate, a lower catalyst layer that is formed on the substrate and contains at least one of Pd and Pt, and an upper catalyst layer that is formed on the lower catalyst layer and contains Rh. A region that does not contain the upper catalyst layer is disposed on the exhaust gas upstream side of this exhaust gas purification catalyst. The lower catalyst layer includes a front-stage lower catalyst layer on the exhaust gas upstream side and a rear-stage lower catalyst layer on the exhaust gas downstream side. The front-stage lower catalyst layer contains an oxygen storage material.

Abstract: Catalyst articles comprising substantially only a palladium precious metal component in a first catalytic layer and a rhodium component in a second catalytic layer and related methods of preparation and use are disclosed. Also disclosed is a catalyst article comprising a first layer formed on a carrier substrate, wherein the first layer comprises a refractory metal oxide and has a surface that is substantially uniform; a second layer formed on the first layer, wherein the second layer comprises i) an oxygen storage component that is about 50-90% by weight of the second layer and ii) a palladium component in an amount of about 2-5% by weight of the second layer, wherein the palladium component is substantially the only platinum group metal component, and a palladium-free third layer comprising a rhodium component supported on a thermostable oxygen storage component which is about 80-99% by weight of the second layer. One or more improved properties are exhibited by the catalyst article.

Abstract: The exhaust gas purification catalyst according to the present invention has a substrate 54, a lower layer 57 disposed on this substrate 54, and an upper layer 58 disposed on this lower layer 57. The upper layer 58 is provided with a first catalyst and a second catalyst, and the lower layer 57 is provided with a first catalyst. This first catalyst has Al2O3 as a carrier and Pt and Pd as noble metals supported on the Al2O3, while the second catalyst typically has an Al2O3—ZrO2—TiO2 complex oxide as a carrier and has Pd as a noble metal supported on the Al2O3—ZrO2—TiO2 complex oxide. Moreover, the upper layer 58 has a hydrocarbon adsorbent 68.

Abstract: Catalyst articles comprising palladium and related methods of preparation and use are disclosed. Disclosed is a catalyst article comprising a first catalytic layer formed on a substrate, wherein the first catalytic layer comprises palladium impregnated on a ceria-free oxygen storage component and platinum impregnated on a refractory metal oxide, and a second catalytic layer formed on the first catalytic layer comprising platinum and rhodium impregnated on a ceria-containing oxygen storage component. The palladium component of the catalyst article is present in a higher proportion relative to the other platinum group metal components. The catalyst articles provide improved conversion of carbon monoxide in exhaust gases, particularly under rich engine operating conditions.

Abstract: An exhaust gas purification catalyst is provided with a catalyst coating layer (40) formed on the surface of a substrate (32). This catalyst coating layer (40) is formed of an upper catalyst coating layer (36) in which Rh particles are supported on a porous support, and a lower catalyst coating layer (34) in which Pd particles are supported on a support that contains an ACZ composite oxide made of alumina (Al2O3), ceria (CeO2), and zirconia (ZrO2).

Abstract: A layered catalyst including a surface axis including a catalyst material layer, and a substrate material layer contacting the catalyst material layer. The catalyst material layer includes a compressed atomic distance between two adjacent catalyst atoms along the surface axis relative to an atomic distance of the same catalyst material as in bulk. The substrate material has a higher surface energy than the catalyst material. In certain instances, at least 70 percent of total atoms of the catalyst material are in a film growth mode. In certain other instances, a surface free energy of the substrate material is 1 to 50 percent greater than a surface free energy of the catalyst material. In yet certain other instances, the catalyst material layer has a d-band center in a range of ?2.1 eV to ?2.25 eV.

Abstract: The present invention relates to a nitrogen oxide storage catalyst comprising: a substrate; a first washcoat layer disposed on the substrate, the first washcoat layer comprising metal oxide support particles and a nitrogen oxide storage material comprising at least one metal compound selected from the group consisting of alkaline earth metal compounds, alkali metal compounds, rare earth metal compounds, and mixtures thereof, at least a portion of said at least one metal compound being supported on the metal oxide support particles; and a second washcoat layer disposed over the first washcoat layer, said second washcoat layer comprising Rh, wherein the first washcoat layer contains substantially no Rh, and wherein the second washcoat layer is disposed on 100-x % of the surface of the first washcoat layer, x ranging from 20 to 80.

Abstract: An emission control catalyst includes copper-ceria to boost low temperature CO oxidation performance, generate exothermic heat during the process, and reduce HC and NOx emissions. As a result, system performance is boosted at equal catalyst cost or maintained at a reduced catalyst cost. In one embodiment, an engine exhaust catalyst includes a first washcoat layer having at least one of a platinum-based catalyst, a palladium-based catalyst, and combinations thereof; and a second washcoat layer having copper-ceria.

Abstract: A NOx storage component comprises caesium silicate (Cs2SiO3) and at least one platinum group metal. The invention also includes a NOx absorber catalyst comprising a NOx storage component according to the invention disposed on a substrate monolith; a method of treating exhaust gas containing NOx from a lean burn internal combustion engine comprising the steps of contacting a NOx storage component comprising caesium silicate (Cs2SiO3) and at least one platinum group metal with lean exhaust gas containing NOx to adsorb NOx thereon; and periodically desorbing adsorbed NOx by contacting the NOx storage component with stoichiometric or rich exhaust gas; and a method of making a NOx storage component according to the invention comprising the steps of combining and reacting an aqueous salt of at least one platinum group metal, an aqueous caesium salt and a source of silica.

Abstract: Systems and methods are provided for a layered emission control device coupled to an exhaust manifold. Various formulations may be incorporated in a plurality of layers of the device to enable various emission control functions to be grouped within spatial constraints. For example, a first layer may include a first, oxidizing catalyst, a second layer may include a HC trap, and a third layer may include a second, different oxidizing catalyst, the second layer positioned between the first and third layers. The layers may be organized to reduce functional interference and improve functional synergy between the various emission control functions.

Abstract: Described is a nitrogen oxide storage catalyst comprising: a substrate; a first washcoat layer provided on the substrate, the first washcoat layer comprising a nitrogen oxide storage material, a second washcoat layer provided on the first washcoat layer, the second washcoat layer comprising a hydrocarbon trap material, wherein the hydrocarbon trap material comprises substantially no element or compound in a state in which it is capable of catalyzing selective catalytic reduction, preferably wherein the hydrocarbon trap material comprises substantially no element or compound in a state in which it is capable of catalyzing a reaction wherein nitrogen oxide is reduced to N2, said catalyst further comprising a nitrogen oxide conversion material which is either comprised in the second washcoat layer and/or in a washcoat layer provided between the first washcoat layer and the second washcoat layer.

Abstract: Catalytic articles, systems and methods for treating exhaust gas streams are described. A catalytic article comprising a wall flow filter having gas permeable walls, a hydrolysis catalyst, an optional soot oxidation catalyst, a selective catalytic reduction catalyst permeating the walls, an ammonia oxidation catalyst and an oxidation catalyst to oxidize CO and hydrocarbons is described. Methods of treating exhaust gas streams comprising soot, an ammonia precursor such as urea, ammonia, NOx, CO and hydrocarbons are also provided.

Abstract: An exhaust gas purifying catalyst that contains a first oxygen storage material on which no noble metal is supported and which has a pyrochlore phase type regular array structure, and a second oxygen storage material which has a higher oxygen storage rate and a lower oxygen storage capacity than the first oxygen storage material and on which a platinum group noble metal is supported.

Abstract: The invention provides a catalyst for catalytically removing three components, which are carbon monoxide, hydrocarbons and nitrogen oxides, from combustion exhaust gas generated by combusting fuel at around the stoichiometric air to fuel ratio. The catalyst includes: (A) a first catalyst component including at least rhodium, platinum, or palladium in a content of 0.01 to 0.5% by weight; and (B) a second catalyst component, which is the remainder, including a composite oxide or a mixed oxide including (a) at least zirconium oxide or titanium oxide, and (b) an oxide of at least praseodymium, yttrium, neodymium, tungsten, niobium, silicon, or aluminum, wherein the content of the oxide (a) in the composite oxide or the mixed oxide is in a range of 70 to 95% by weight. The invention further provides a two-layer catalyst that includes a surface catalyst layer containing the above-mentioned catalyst.

Abstract: A double-layer three-way catalyst for purification of the exhaust gases from internal combustion engines which has excellent activity and thermal stability is described. The catalyst contains active aluminum oxide and a first cerium/zirconium mixed oxide which are both catalytically activated with palladium in the first layer applied to a catalyst support. In the second layer which is in direct contact with the exhaust gas, the catalyst likewise contains an active aluminum oxide and a second cerium/zirconium mixed oxide which are both catalytically activated with rhodium. The second cerium/zirconium mixed oxide has a higher zirconium oxide content than the first mixed oxide.

Abstract: Disclosed herein is a catalytically active particulate filter, an exhaust gas cleaning system and a process for cleaning the exhaust gases of predominantly stoichiometrically operated internal combustion engines, which are suitable, as well as the gaseous CO, HC and NOx pollutants, also for removing particulates from the exhaust gas. The particulate filter comprises a filter body and a catalytically active coating consisting of two layers. The first layer is in contact with the incoming exhaust gas, the second layer with the outgoing exhaust gas. Both layers contain alumina. The first layer contains palladium. The second layer contains, in addition to rhodium, an oxygen-storing cerium/zirconium mixed oxide.

Abstract: An exhaust gas purifying catalyst is constituted by: noble metal particles (1); first compounds (2) which support the noble metal particles (1); second compounds (3) different in type from the first compounds (2); and oxides (4) which surround the noble metal particles (1), the first compounds (2) and the second compounds (3). A median diameter of the first compounds (2) and a median diameter of the second compounds (3) satisfy a relationship of a following inequality: median diameter of first compounds<median diameter of second compounds.

Abstract: An exhaust gas-purifying catalyst according to the present invention includes a substrate, a first catalytic layer facing the substrate and includes at least one precious metal selected from the group consisting of palladium and platinum, and alumina doped with an alkaline-earth metal element, and a second catalytic layer facing the substrate with the first catalytic layer interposed therebetween or intervening between the substrate and the first catalytic layer, the second catalytic layer includes rhodium and alumina doped with the alkaline-earth metal element.

Abstract: Provided are catalyst composites that can be used in methods for treating exhaust gas from internal combustion engines, including diesel and gasoline engines, systems including such catalyst composites and methods of using the catalyst composites to treat internal combustion engine exhaust. The catalyst composites may provide diesel oxidation catalysts and three-way catalysts. A catalyst composite is provided which a catalytic material on a carrier, the catalytic material including a palladium component dispersed on a first support comprising at least 60% by weight of a zirconia component, and one or more rare earth oxides selected from the group consisting of lanthana, neodymia, praseodymia, yttria, the first support optionally containing no more than 15% by weight ceria, and being free of alumina. Layered catalyst composites having one or more washcoats on the carrier are also provided.

Abstract: Disclosed herein is a layered, three-way conversion catalyst having the capability of simultaneously catalyzing the oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides being separated in a front and rear portion is disclosed. Provided is a catalytic composite material of a single front and two rear layers in conjunction with a substrate, where each of the layers includes a support, all layers comprise a platinum group metal component, and the rear bottom layer is substantially free of an oxygen storage component (OSC).

Abstract: A device is described which provides thermally durable NO2 generation in conjunction with efficient heat-up performance for filter regeneration, and low temperature HC (hydrocarbon) and CO activity. Importantly, it provides both functions while minimizing PGM (platinum group metals) utilization and its associated impact on catalyst cost.

Abstract: An exhaust gas purification catalyst includes: a lower catalyst layer that contains a ceria-zirconia mixed oxide having 50 to 70 mass % of CeO2 and 5 mass % or more of Pr2O3 and carries at least one of Pt and Pd; and an upper catalyst layer that contains at least zirconia and carries at least Rh, wherein the total amount of CeO2 per liter of the carrier base is 15 to 30 g. Because the amount of CeO2 is small, formation of H2S is suppressed and a high capability of adsorbing and releasing oxygen is brought out in spite of the small amount of CeO2.

Abstract: It is intended to highly efficiently produce a high-density brush shaped carbon nanostructure useful in the production of CNT assembly, such as rope-shaped CNTs, and provide a catalyst body for production of brush-shaped carbon nanostructure that enables the production. The catalyst body for production of brush-shaped carbon nanostructure is one comprising a substrate (32), an aggregation suppressive layer (34) superimposed on a surface thereof and a catalyst layer superimposed on the aggregation suppressive layer (34). The catalyst layer is a catalyst particle layer (44) consisting of metallic catalyst particles (42) composed mainly of a catalytic metal. The metallic catalyst particles (42) have an average particle diameter, D, satisfying the relationship 0.5 nm?D?80 nm, and individual particles of the metallic catalyst particles (42) have a diameter, d, falling within the range of the above average particle diameter (D).

Abstract: An exhaust aftertreatment system for a lean-burn engine may include a lean NOX trap that comprises a catalyst material. The catalyst material may remove NOX gases from the engine-out exhaust emitted from the lean-burn engine. The catalyst material may include a NOX oxidation catalyst that comprises a perovskite compound.

Abstract: A catalyst for treating exhaust gases containing nitrogen monoxide, carbon monoxide and volatile organic compounds includes a plurality of layers, an upper layer of which has an active component contained uniformly therein and a lower layer of which has no active component contained therein. The catalyst is obtained through the steps of: forming the lower layer by coating the surface of substrate with a slurry of a porous inorganic compound, followed by drying; and forming the upper layer, which is to be the top surface of the catalyst, by coating the surface of the lower layer with a slurry of a porous inorganic compound that has the active component composed of one or more precious metals supported thereon, followed by drying. The oxidation power of the resulting catalyst is enhanced without increasing the amount of precious metal supported thereon.

Abstract: An exhaust gas purifying catalyst 1 has a catalyst substrate 3 and catalyst coating layers 5, 7 that are formed on the catalyst substrate 3 and contain (a) Rh, (b) Pt, (c) an alkali metal or alkaline earth element, and (d) an inorganic oxide. The catalyst coating layers 5, 7 has a layered structure including an inside layer 5 where the component (a) is substantially locally existing, and an outside layer 7 where the component (b) is substantially locally existing. The inside layer 5 also contains a zirconia oxide.

Abstract: Systems and methods are provided for a layered emission control device coupled to an exhaust manifold. Various formulations may be incorporated in a plurality of layers of the device to enable various emission control functions to be grouped within spatial constraints. For example, a first layer may include a first, oxidizing catalyst, a second layer may include a HC trap, and a third layer may include a second, different oxidizing catalyst, the second layer positioned between the first and third layers. The layers may be organized to reduce functional interference and improve functional synergy between the various emission control functions.

Abstract: An exhaust gas purifying catalyst includes a monolithic substrate (2), and a transition metal oxide layer (3) formed in the monolithic substrate (2). The transition metal oxide layer (3) contains transition metal oxide powder including: transition metal oxide particles (10); a first compound (20) on which the transition metal oxide particles (10) are supported; and a second compound (30) that surrounds a single body or an aggregate of the transition metal oxide particles (10) and the first compound (20).

Abstract: Diesel oxidation catalysts comprising a first washcoat layer including a platinum group metal impregnated on a promoted non-zeolitic support are described. The promoter is one or more of tin, manganese, indium, group VIII metals. Methods of making and using the diesel oxidation catalyst, including emissions treatment systems, are also described.

Abstract: A sulfur tolerant oxidation catalyst with appreciable NO and HC oxidation capabilities has been developed for use in any component of an exhaust aftertreatment system for a lean-burn engine where the oxidation of at least NO is desired. Several non-exclusive examples of such components where the oxidation catalyst may be employed include a DOC and a LNT. The oxidation catalyst may comprise perovskite oxide particles that support palladium particles. The ability of the palladium supported perovskite oxide particles to concurrently oxidize NO and HC's can significantly diminish or altogether eliminate the use of platinum in the exhaust aftertreatment system for at least NO oxidation. The oxidation catalyst, moreover, may exhibit superior thermal durability and better NO and HC oxidation activities than platinum in some instances.

Abstract: An exhaust gas purification catalyst includes a substrate, and a first catalyst layer formed on the substrate, the first catalyst layer containing palladium and/or platinum and alumina doped with an alkaline-earth metal element. The exhaust gas purification catalyst has a correlation coefficient ?Al,AE given by the following formula of 0.75 or more: ? Al , AE = C Al , AE ? Al ? ? AE .

Abstract: A catalyzed diesel particulate filter (CDPF) and a method for filtering particulates from diesel engine exhaust are provided, where the catalyzed diesel particulate filter includes a substrate and a catalyst composition, where the catalyst composition contains at least one first component, at least one second component, and at least one third component, where the first component is at least one first component selected from the group consisting of cerium and a lanthanide and mixtures thereof, the at least one second component is selected from the group consisting of cobalt, copper, manganese and mixtures thereof; and the third component comprises strontium, where the first component, the second component, and the third component are in an oxide form after calcination. The catalyst on the catalyzed diesel particulate filter lowers the temperature at which particulates are removed from the CDPF by oxidizing the particulates on the filter. The catalyzed diesel particulate filter may also include a washcoat.

Abstract: An exhaust gas purifying catalyst includes a catalyst substrate and a catalyst coating layer containing a noble metal and a refractory inorganic oxide. The catalyst coating layer includes an upstream portion located upstream and a downstream portion located downstream in a flow direction of an exhaust gas. The upstream portion has a layered structure including an upstream portion inside layer containing a cerium-zirconium composite oxide in which a relative proportion of CeO2 is 50 to 95 wt %, as the refractory inorganic oxide and an upstream portion outside layer containing a cerium-zirconium composite oxide in which a relative proportion of ZrO2 is 50 to 95 wt %, as the refractory inorganic oxide. The upstream portion outside layer and the downstream portion contain Rh as the noble metal, and an amount of Rh contained in the upstream portion outside layer is larger than an amount of Rh contained in the downstream portion.

Abstract: One aspect of the present invention relates to a system for remediating emissions using a hybrid oxidation catalyst system. The hybrid oxidation catalyst system includes a noble metal oxidation catalyst having noble metal particles in a first ceramic layer. The system also includes a base metal oxide catalyst disposed in a second ceramic layer situated downstream of the noble metal oxidation catalyst. The noble metal oxidation catalyst is effective to substantially prevent hydrocarbon or carbon monoxide inhibition of the base metal oxide catalyst when enhancing the NO+O2 conversion effectiveness of the base metal oxide catalyst.

Abstract: An exhaust gas purifying catalyst includes: rhodium; a zirconium-containing oxide which supports rhodium, and comprises: at least one element selected from the group consisting of calcium, lanthanum, cerium, neodymium and yttrium; and zirconium; and a NOx absorbing material comprising at least one selected from the group consisting of magnesium, barium, sodium, potassium and cesium. A degree of dispersion of rhodium is 20% or more after baking at 900° C. in air for three hours. A method for manufacturing the exhaust gas purifying catalyst includes: mixing the zirconium-containing oxide with water, thereby preparing an aqueous liquid of the zirconium-containing oxide; and supporting rhodium on the zirconium-containing oxide by mixing the aqueous liquid of the zirconium-containing oxide with an aqueous solution of a rhodium salt. A pH of a mixed liquid of the aqueous solution of the rhodium salt and the aqueous liquid of the zirconium-containing oxide is adjusted to 7 or more.

Abstract: To provide a catalyst for treating exhaust gases containing nitrogen monoxide, carbon monoxide and volatile organic compounds whose oxidation power has been enhanced without increasing the amount of precious metal supported thereon; a method for producing the same; and a method for treating exhaust gases. A catalyst for treating exhaust gases, including coat layers made up of a plurality of layers, an upper layer of which has an active component contained uniformly therein and a lower layer of which has no active component contained therein, can be obtained through the steps of: forming the lower layer by coating the surface of substrate with a slurry of a porous inorganic compound, followed by drying; and forming the upper layer, which is to be the top surface of the catalyst, by coating the surface of the lower layer with a slurry of a porous inorganic compound that has the active component composed of one or more precious metals supported thereon, followed by drying.

Abstract: An emission control catalyst that exhibits improved CO and HC reduction performance includes supported precious group metal catalysts that are coated onto different layers of the substrate for the emission control catalyst. Zeolites of one or more types are added to the emission control catalyst as a hydrocarbon absorbing component to boost the low temperature performance of the emission control catalyst. Y zeolite is used by itself or mixed with other zeolites to enhance hydrocarbon storage at low temperatures.