Toyota Jidosha Kabushiki Kaisha

Cataler Corporation

Isao Naito

Hiroki Nihashi

Masahide Miura

Shogo Shirakawa

Norimichi Shimano

Isao Chinzei

Seiji Nakahigashi

Hiromi Togashi

Mitsuyoshi Okada

Takashi Onozuka

Takahiro Nishio

Tomomasa Aikawa

Souta Akiyama

Hiromasa Suzuki

Nobuyuki Takagi

Akiya Chiba

Shogo Kawamura

Motoya Abe

Takaaki Kanazawa

Takeshi Nobukawa

Takahiro Noguchi

Shunsuke Haga

A supported catalyst particles include oxide carrier particles and noble metal particles supported on the oxide carrier particles, wherein the mass of the noble metal particles is less than or equal to 5 mass % based on the mass of the oxide carrier particles, and the average particle size of the noble metal particles measured by transmission electron microscopy is 1.0-2.0 nm, with the standard deviation σ less than or equal to 0.8 nm.

Supported catalyst particles

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 Ris 0.5 or more, where Rrepresents the Pearson's correlation coefficient calculated using &#x3b1; and &#x3b2; 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 &#x3bc;m&#xd7;0.34 &#x3bc;m; and number of measured pixels 256&#xd7;256; and measuring an intensity (&#x3b1;: cps) of a characteristic X ray of an element (Ae) of the alkaline-earth metal and an intensity (&#x3b2;: cps) of a characteristic X ray of Pt for each pixel.

Exhaust gas purification catalyst

The present disclosure provides an exhaust gas purification catalyst having improved durability, which comprises a substrate and a catalyst coat layer formed on the substrate, the catalyst coat layer having a two-layer structure, wherein the catalyst coat layer includes an upstream portion on an upstream side and a downstream portion on a downstream side in an exhaust gas flow direction, and a part or all of the upstream portion is formed on a part of the downstream portion, wherein the downstream portion contains Rh fine particles, and wherein the Rh fine particles have an average particle size measured by a transmission electron microscope observation of 1.0 nm or more to 2.0 nm or less, and a standard deviation &#x3c3; of the particle size of 0.8 nm or less.

The present disclosure provides an exhaust gas purification catalyst having an improved Rh activation, which comprises a substrate and a catalyst coat layer formed on the substrate, the catalyst coat layer having a two-layer structure, wherein the catalyst coat layer includes an upstream portion on an upstream side and a downstream portion on a downstream side in an exhaust gas flow direction, and a part or all of the upstream portion is formed on a part of the downstream portion, wherein the upstream portion contains Rh fine particles and Pt, wherein the Rh fine particles have an average particle size measured by a transmission electron microscope observation of 1.0 nm or more to 2.0 nm or less, and a standard deviation &#x3c3; of the particle size of 0.8 nm or less, and wherein the downstream portion contains Rh.

The present disclosure relates to an exhaust gas control catalyst including a base and a catalyst coating layer having a two-layer structure on the base. The catalyst coating layer includes a lower layer on the base, and an upper layer on the lower layer. The upper layer of the catalyst coating layer contains Rh particles in which a mean particle diameter measured by observation using a transmission electron microscope is 1.0 nm or more and 2.0 nm or less and a particle-diameter standard deviation &#x3c3; is 0.8 nm or less. A length of the upper layer from an end face on a downstream side in an exhaust gas flow direction falls within a range of 70% or more and 100% or less of a total length of the base.

Exhaust gas control catalyst

The present disclosure provides an exhaust gas purification catalyst having an improved low-temperature activity, which comprises a substrate and a catalyst coat layer formed on the substrate, wherein the catalyst coat layer contains Rh fine particles and a promoter comprising a Ce&#x2014;Zr-based composite oxide and a Zr-based composite oxide not containing cerium oxide, wherein the Rh fine particles have an average particle size measured by a transmission electron microscope observation of 1.0 nm or more to 2.0 nm or less, and a standard deviation &#x3c3; of the particle size of 0.8 nm or less, and wherein the Rh fine particles are supported on each of the Ce&#x2014;Zr-based composite oxide and the Zr-based composite oxide not containing cerium oxide.

An exhaust gas purifying catalyst with an excellent effect of suppressing deterioration due to aggregation of a noble metal catalyst during endurance at high temperature, and a production method therefor. The method for producing the exhaust gas purifying catalyst that has a porous carrier and a noble metal catalyst supported thereon includes: preparing the porous carrier that contains alumina-ceria-zirconia composite oxide particles and has physical property values, after subjected to baking at 900&#xb0; C. for 5 hours, of a pore diameter of the particles in the range of 2 to 20 nm, a specific surface area of the particles in the range of 75 to 115 m/g, a crystallite size of a ceria-zirconia composite oxide contained in the particles in the range of 4 to 6 nm, and a bulk density of the particles in the range of 0.5 to 0.9 cm/g, and bringing a noble metal chemical solution having an aggregate of platinum or the like with a grain size adjusted to less than or equal to 1 nm with the use of a platinum nitric acid solution or the like, into contact with the porous carrier, so that the noble metal catalyst is supported on the porous carrier.

Exhaust gas purifying catalyst and method for producing the same

A rhodium-loading solution characterized by comprising rhodium atoms and an organic base in a molar ratio of 1:0.5-35.

Growing community of inventors

Kakegawa, Japan

Isao Naito