The present invention relates to a composite oxide comprising ceria, praseodymia and alumina, wherein the cerium:praseodymium molar ratio of the composite oxide is 84:16 or less, as well as to a method of preparing the composite oxide and to its use, in particular in a method of treating an exhaust gas stream.

The present disclosure provides a monolith substrate used for an exhaust gas purifying catalyst that improves purification performance, a method for producing such monolith substrate, and an exhaust gas purifying catalyst comprising such monolith substrate. The present disclosure relates to a monolith substrate comprising an alumina-ceria-zirconia composite oxide and alumina, a method for producing such monolith substrate, and an exhaust gas purifying catalyst comprising such monolith substrate.

Zero-Rare Earth Metal (ZREM) and Zero-platinum group metals (ZPGM) compositions of varied binary spinel oxides are disclosed as oxygen storage material (OSM) to be used within TWC systems. The ZREM-ZPGM OSM systems comprise binary non-Cu spinel oxides of Co—Fe, Fe—Mn, Co—Mn, or Mn—Fe. The oxygen storage capacity (OSC) property associated with the non-Cu ZREM-ZPGM OSM systems is determined employing isothermal OSC oscillating condition testing. Further, the OSC test results compare the OSC properties of a ZREM-ZPGM reference OSM system including a Cu—Mn binary spinel oxide and PGM reference catalysts including Ce-based OSMs. The non-Cu spinel oxides ZREM-ZPGM OSM systems exhibit significantly improved OSC properties, which are greater than the OSC property of the Ce-based OSM PGM reference systems.

A lean gasoline exhaust treatment catalyst article is provided, the article comprising a catalytic material applied on a substrate, wherein the catalytic material comprises a first composition and a second composition, wherein the first and second compositions are present in a layered or zoned configuration, the first composition comprising palladium impregnated onto a porous refractory metal oxide material and rhodium impregnated onto a porous refractory metal oxide material; and the second composition comprising platinum impregnated onto a porous refractory metal oxide material. Methods of making and using such catalyst articles and the associated compositions and systems employing such catalyst articles are also described.

The present invention relates to cerium oxide particles that have excellent heat resistance especially useful for catalysts, functional ceramics, solid electrolyte for fuel cells, polishing, ultraviolet absorbers and the like, and particularly suitable for use as a catalyst or co-catalyst material, for instance in catalysis for purifying vehicle exhaust gas. The present invention also relates to a method for preparing such cerium oxide particles, and a catalyst, such as for purifying exhaust gas, utilizing these cerium oxide particles.

An object of at least one embodiment of the present invention is to suppress poisoning due to phosphorus derived from engine oil, and effectively purify NOx discharged from the time of engine start up to a high load condition. In an exhaust gas purification catalyst for an internal combustion engine, a catalyst layer includes: a first catalyst layer exposed to an exhaust gas flow; and a second catalyst layer formed between the first catalyst layer and the substrate. A second catalyst upstream layer formed on an upstream side of the second catalyst layer with respect to the exhaust gas flow and a first catalyst downstream layer formed on a downstream side of the first catalyst layer with respect to the exhaust gas flow include at least one of palladium and platinum, as well as an oxygen storage material as the catalyst component. An amount of the oxygen storage material in the first catalyst downstream layer is larger than an amount of the oxygen storage material in the second catalyst upstream layer.

An object is to provide an exhaust gas purification catalyst for an internal combustion engine that can achieve a higher exhaust gas purification performance and a higher engine output performance. A catalyst layer is disposed in an exhaust gas passage, formed on a surface of the substrate, and includes: a first catalyst layer exposed to an exhaust gas flow; and a second catalyst layer formed between the first catalyst layer and the substrate. A catalyst component supported on the first catalyst layer includes rhodium. A catalyst component supported on the second catalyst layer includes at least one of palladium and platinum. The first catalyst layer is formed such that a density of the rhodium supported thereon decreases in a step-like manner through a plurality of segment zones segmented along an exhaust gas flow direction, and the second catalyst layer is formed such that a density of the palladium or the platinum supported thereon decreases in a step-like manner through a plurality of segment zones segmented along the exhaust gas flow direction.

The presently claimed invention provides a layered three-way catalyst composition for purification of exhaust gases from internal combustion engines; said catalyst comprises a first layer comprising i) palladium supported on at least one alumina component and at least one oxygen storage component; and ii) barium oxide; wherein said first layer is essentially free of strontium, and a second layer comprising: i) rhodium supported on at least one zirconia component and/or alumina component; ii) strontium oxide and/or barium oxide; and iii) optionally, palladium supported on at least one alumina component. The presently claimed invention also provides a process for preparing the layered three-way catalyst composition which involves a technique such as incipient wetness impregnation technique(A); co-precipitation technique (B); or co-impregnation technique(C). The process includes preparing a first layer; preparing a second layer; and depositing the second layer on the first layer followed by calcination. The presently claimed invention further provides a a layered three-way catalytic article in which the three-way catalyst composition is deposited on a substrate in a layered fashion and its preparation.

A multi-scaled oxygen storage material wherein cobalt element is complexed with a size of an atom or hundreds of nanometers or smaller in a ceria-zirconia solid solution and a method for preparing the same are provided.

Specifically, The multi-scaled oxygen storage material contains a ceria-zirconia solid solution, a cobalt dopping contained in the solid solution in the form of an atom and a cobalt-based nanocluster dispersed in the solid solution as cobalt oxide and exhibits a microstructure distinguished from that of the existing ceria-zirconia (CZO)-based oxygen storage material as well as remarkably improved oxygen storage and release ability, and the method for preparing the same is provided.

A catalytic converter with excellent OSC performance and No.sub.x purification performance. The catalytic converter includes a substrate with a cell structure and a catalyst layer formed on a cell wall surface of the substrate. The catalyst layer has a catalyst layer arranged on the upstream side and a catalyst layer arranged on the downstream side in an exhaust gas flow direction on the substrate. The catalyst layer on the upstream side includes a support containing an Al.sub.2O.sub.3—CeO.sub.2—ZrO.sub.2 ternary composite oxide (ACZ material) and an Al.sub.2O.sub.3—ZrO.sub.2 binary composite oxide (AZ material), and at least Rh that is a noble metal catalyst carried on the support, and the catalyst layer on the downstream side includes a support and Pd or Pt that is a noble metal catalyst carried on the support. In the support in the catalyst layer on the upstream side, the mass proportion of ACZ material/(ACZ material+AZ material) is in the range of 0.33 to 0.5, and greater than or equal to 75% mass Rh is carried on the Al.sub.2O.sub.3—ZrO.sub.2 binary composite oxide of the support.