Cataler Corporation

Toyota Jidosha Kabushiki Kaisha

Takashi Onozuka

Masahide Miura

Mitsuyoshi Okada

Isao Chinzei

Seiji Nakahigashi

Hiromasa Suzuki

Akira Morikawa

Satoru Katoh

Shogo Shirakawa

Toshio Yamamoto

Isao Naito

Hiroki Nihashi

Takahiro Nishio

Norimichi Shimano

Hiromi Togashi

Souta Akiyama

Hirotaka Ori

Sho Hoshino

Kenichi Taki

Nobuyuki Takagi

Nobusuke Kabashima

Takahiro Noguchi

Kyosuke Murakami

A catalyst for purification of exhaust gas including a substrate, and a catalyst coat layer which is formed on a surface of the substrate and contains catalyst particles, wherein the catalyst coat layer has an average thickness ranging 25 to 150 μm, a void fraction, as determined by scanning electron microscope observation of a cross-section of the catalyst coat layer, ranging 1.5 to 8.0% by volume, 60 to 90% by volume of all voids in the catalyst coat layer are high-aspect ratio pores which have equivalent circle diameters ranging 2 to 50 μm in a cross-sectional image of a cross-section of the catalyst coat layer perpendicular to a flow direction of exhaust gas in the substrate, and which ratios of 5 or higher, the high-aspect ratio pores have an average aspect ratio ranging 10 to 50, and a noble metal is supported on the entire catalyst coat layer.

Catalyst for purification of exhaust gas

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.

Exhaust gas purification catalyst

The present disclosure provides the exhaust gas purification catalyst with the improved purification performance under the high Ga condition and the transient state in which an A/F repeats rich and lean phases. The present disclosure relates to an exhaust gas purification catalyst comprising a catalyst coating layer on a substrate, the catalyst coating layer containing a noble metal, a composite oxide containing cerium oxide and zirconium oxide, and a composite oxide containing aluminum oxide, wherein in the catalyst coating layer: an average thickness of the coating layer is in a range from 20 &#x3bc;m to 100 &#x3bc;m; a porosity measured by a weight-in-water method is in a range from 50% by volume to 80% by volume; and high-aspect-ratio pores having an aspect ratio of 5 or more account for 0.5% by volume to 50% by volume of a whole volume of voids, the high-aspect-ratio pore having an equivalent circle diameter in a range from 2 &#x3bc;m to 50 &#x3bc;m in a cross-sectional image of a catalyst coating layer cross section perpendicular to an exhaust gas flow direction of the substrate and having an average aspect ratio in a range from 10 to 50, and wherein the noble metal is supported on peripheries of the voids, the composite oxide containing the cerium oxide and the zirconium oxide, and the composite oxide containing the aluminum oxide.

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.

The present disclosure provides the exhaust gas purification catalyst with the improved purification performance under the high Ga condition and the atmosphere where the A/F is rich. The present disclosure relates to an exhaust gas purification catalyst including a catalyst coating layer on a substrate, the catalyst coating layer containing a noble metal and a metal oxide, wherein in the catalyst coating layer: an average thickness of the coating layer is in a range from 50 &#x3bc;m to 100 &#x3bc;m; a porosity measured by a weight-in-water method is in a range from 50% by volume to 80% by volume; and high-aspect-ratio pores having an aspect ratio of 5 or more account for 0.5% by volume to 50% by volume of a whole volume of voids, the high-aspect-ratio pore having an equivalent circle diameter in a range from 2 &#x3bc;m to 50 &#x3bc;m in a cross-sectional image of a catalyst coating layer cross section perpendicular to an exhaust gas flow direction of the substrate and having an average aspect ratio in a range from 10 to 50, and wherein when a surface side in contact with an exhaust gas in a thickness direction of the catalyst coating layer is defined as 0% and a side in contact with the substrate is defined as 100%, 80% by mass or more of a total amount of the noble metal is present in a range from 0% to 25% or more and 70% or less.

An exhaust gas purifying catalyst according to the present invention is provided with a base materialand a catalyst-coated layer. The catalyst-coated layeris provided with a lower layerand an upper layer. The upper layercontains Rh and/or Pt as a noble metal catalyst. The lower layercontains Pd as a noble metal catalyst. The lower layeris provided with a front-stage lower layerpositioned on an upstream side and a rear-stage lower layerpositioned on a downstream side. The front-stage lower layeris a Ce-free layer that does not contain a Ce-containing oxide. The rear-stage lower layeris a Ce-containing layer that contains a Ce-containing oxide with a pyrochlore structure.

Exhaust gas purifying catalyst

Growing community of inventors

Kakegawa, Japan

Takashi Onozuka