摘要:
A particulate inorganic mixed oxide comprising: aluminum; zirconium; cerium; and first and second additional elements each selected from the group consisting of rare earth elements other than cerium and alkaline earth elements, wherein a content of aluminum in the inorganic mixed oxide is 60 to 90 at%, in terms of element content, relative to a total amount of elements which form cations in the inorganic mixed oxide; a content of cerium in the inorganic mixed oxide is 0.4 to 50 at%, in terms of element content, relative to a total amount of zirconium and cerium in the inorganic mixed oxide; a content of a total amount of the first and second additional elements is 1 to 12 at%, in terms of element content, relative to the total amount of the elements which form cations in the inorganic mixed oxide; at least 80% of primary particles of the inorganic mixed oxide have a particle diameter of 100 nm or less; at least a part of the primary particles have an enriched surface region where a content of the second additional element is locally increased in a surface layer portion thereof; and an amount of the second additional element in the enriched surface region is 0.1 to 0.95% by mass, in terms of oxide, relative to a whole amount of the inorganic mixed oxide.
摘要:
Disclosed is an exhaust gas purifying catalyst wherein a catalyst coat layer composed of at least two layers including an upper layer and a lower layer is formed on a base. The upper layer contains more noble metal than the lower layer per 1 L of the base, and the lower layer contains more oxygen storage/release material than the upper layer per 1 L of the base. This exhaust gas purifying catalyst exhibits more excellent H2S purifying performance than conventional catalysts, while maintaining purifying performance for other exhaust gases such as NOx.
摘要:
The exemplary embodiments relate to an exhaust gas purification catalyst, in which exhaust gas purification performance is secured and an increase in pressure loss is suppressed, which is an exhaust gas purification catalyst, in which a porous filter wall of a substrate having a wall-flow structure is coated with a catalyst material containing an OSC material having oxygen storage capacity and a catalyst metal, wherein the density of percolation paths having percolation path diameters of 4 µm or more per unit area inside of the filter wall coated with the catalyst material is 100 paths/mm 2 to 1000 paths/mm 2 .
摘要:
An exhaust gas purifying catalyst includes a substrate (1) that defines an exhaust gas passage; a lower catalyst layer (2) formed over the substrate, and an upper catalyst layer (3) formed over the lower catalyst layer (2). The lower catalyst layer (2) has a lower catalytic precious metal that contains at least one of Pt and Pd, and a lower-layer carrier that supports the lower catalytic precious metal. The upper catalyst layer (3) has an upper catalytic precious metal that contains Rh, and an upper-layer carrier that supports the upper catalytic precious metal. The upper-layer carrier comprises an inorganic mixed oxide that contains Ce, Zr, Al, Nd, and at least one element selected from the group consisting of rare earth elements other than Ce. The inorganic mixed oxide has interior regions containing a mixed aggregate composed of first particles comprising Ce and Zr in a form of a composite oxide, and second particles comprising Al in a form of alumina, and has cover layers containing Nd that cover surfaces of the respective interior regions. The Nd is unevenly present in the cover layers or the Nd is concentrated in the cover layers.
摘要:
A catalyst for purifying exhaust gases includes a substrate, and a catalytic layer. The catalytic layer includes a lower catalytic layer, a first upper catalytic layer, and a second upper catalytic layer. The lower catalytic layer being loaded with Pd and/or Pt is formed on the substrate. The first upper catalytic layer being loaded with Pd covers an upstream side of the lower catalytic layer, and exhibits a concentration of loaded Pd that falls in a range of from 4.5 to 12% by mass when the entirety of the first upper catalytic layer is taken as 100% by mass. The second upper catalytic layer being loaded with Rh covers a downstream side of the lower catalytic layer.
摘要:
An excellent oxygen storage capacity is achieved even in the case used for a long period of time under high temperature conditions. An oxygen storage material contains a first particle made of a composite oxide of cerium and zirconium or a composite oxide of cerium, a rare-earth element other than cerium and zirconium, a second particle including a composite oxide of a rare-earth element, an alkaline-earth element and zirconium, and a precious metal. A part of the precious metal forms a solid solution with the composite oxide included in the second particle.
摘要:
An exhaust gas purification catalyst apparatus 100 has a honeycomb base material and a catalyst noble metal supported by the honeycomb base material, wherein: the honeycomb base material contains ceria-zirconia composite oxide particles as one of the constituent materials, is of a wall flow type, and includes inlet-side cells 21 and outlet-side cells 22 demarcated by porous partition walls 10; the catalyst noble metal is supported in inlet-side support regions 30 and outlet-side support regions 40; each of the inlet-side support regions 30 is formed with a specific length 31 from the exhaust gas flow upstream end; the catalyst noble metal 70% support depth is not greater than 50% of the thickness of the porous partition walls 10; each of the outlet-side support regions 40 is formed with a specific length 41 from the exhaust gas flow downstream end; and the catalyst noble metal 70% support depth is greater than 50% of the thickness of the porous partition walls 10.