Cataler Corporation

Daihatsu Motor Company, Ltd.

Santoku Corporation

Satoshi Matsueda

Kenichi Taki

Akimasa Hirai

Keiichi Narita

Mareo Kimura

Sho Hoshino

Yuji Yabuzaki

Hirohisa Tanaka

Mari Uenishi

Masashi Taniguchi

Naoto Miyoshi

Isao Tan

Asuka Hori

Masahiro Kusaka

Chihiro Kasuya

Yu Sakurada

Yoshinori Ishii

Akiya Chiba

Tadatoshi Murota

Ryota Nakashima

Daisuke Ochiai

Tomohito Mizukami

Satoru Inoda

Kyosuke Murakami

Michio Tanaka

Shigeru Ono

Hiroki Nagashima

Hiroto Yoshida

Tomonori Tahara

Takashi Goto

Koki Yanagawa

Mari Uenisha

Takara Misumi

Ryouhei Iwasaki

A Pd-supporting Zr-based composite oxide wherein by having a Zr-containing composite oxide support and Pd supported thereon and by showing, upon XAFS (X-ray absorption fine structure) analysis, a maximum peak in a Pd bond distance range of 2.500-3.500 &#x212b;, the maximum peak being located in a position of 3.050-3.110 &#x212b;.

Pd-supporting Zr-based composite oxide

A novel exhaust gas purifying catalyst, method for producing same, and an exhaust gas purification device using same, which are capable of maintaining catalytic activity of a precious metal at a higher level than compared with conventional exhaust gas purifying catalysts. An exhaust gas purifying catalyst having a first carrier particle, a second carrier particle, and a precious metal catalyst particle carried on the first and second carrier particles, wherein: the first carrier particle contains a rare-earth oxide other than ceria and at least one metal oxide selected from the group consisting of silica, alumina, ceria, zirconia, and titania; the second carrier particle contains a rare-earth oxide other than ceria; and the contained amount of the rare-earth oxide in the second carrier particle is higher than the contained amount of the rare-earth oxide in the first carrier particle.

Exhaust gas purifying catalyst and method for producing same, and exhaust gas purification device using same

An exhaust gas purification catalyst, characterized by having a catalyst layer containing palladium, rhodium, and alumina, which supports a sulfate of an alkaline-earth metal selected from barium sulfate and strontium sulfate, and the correlation coefficients &#x3c1;and &#x3c1;calculated from the characteristic X-ray intensity measured using an electron beam micro-analyzer for the palladium, rhodium, and alkaline-earth metal being +0.75 to +1.00 and 0.00 to +0.25, respectively, using 350 points as measurement points obtained by equally dividing the catalyst layer into 351 parts in the thickness direction on a virtual straight line that runs through the catalyst layer in the thickness direction.

Exhaust gas purification catalyst

An exhaust-gas purifying catalyst includes a lower layer containing ceria-based oxide particles and an upper layer containing metal oxide particles and a precious metal supported on the metal oxide particles, wherein the exhaust-gas purifying catalyst is characterized in that the Rh content of the lower layer is equal to or less than 0.25 g/L, and also that the particle-size distribution of the ceria-based oxide particles in the lower layer, which is obtained by scanning electron microscopy, has a first peak in which the peak top thereof is in a region of 0.90-6.50 &#x3bc;m and a second peak in which the peak top thereof is in a region of 9.50-34.0 &#x3bc;m.

Exhaust-gas purifying catalyst and manufacturing method therefor

An exhaust gas purification device which has improved exhaust gas purification performance. An exhaust gas purification device which includes a first catalyst layer that contains: a Pd-supporting catalyst which is obtained by having alumina carrier particles support Pd; a first Rh-supporting catalyst which is obtained by having first ceria-zirconia carrier particles support Rh; and second ceria-zirconia carrier particles. This exhaust gas purification device is configured such that: the ceria concentration in the first ceria-zirconia carrier particles is 30 wt % or less; and the amount of ceria in the second ceria-zirconia carrier particles is larger than the amount of ceria in the first ceria-zirconia carrier particles.

Exhaust gas purification device

An exhaust gas-purifying catalyst includes a support and a catalytic metal supported thereby. The support includes a composite oxide represented by AO.xBCO, wherein A represents at least one of an element having a valence of 1 and an element having a valence of 2, B represents an element having a valence of 3, C represents one or more elements selected from iridium, ruthenium, tantalum, niobium, molybdenum, and tungsten, x represents a numerical value of 1 to 6, and &#x3b1; represents a numerical value greater than 0 and less than 2. The catalytic metal includes one or more precious metals selected from rhodium, palladium, and platinum.

Exhaust gas-purifying catalyst

An exhaust gas-purifying catalyst of the present invention comprises a substrate, and one or more catalytic layers provided on the substrate, wherein at least one of the catalytic layers (i) contains a precious metal, alumina, and an acidic oxide element, (ii) has a correlation coefficient &#x3c1;of 0.70 or more, and (iii) has a correlation coefficient &#x3c1;of 0.70 or more.

An exhaust gas-purifying catalyst includes a support and a catalytic metal as one or more precious metals supported by the support. The support includes a composite oxide having a composition represented by a general formula ABCO, wherein A represents one or more elements selected from the group consisting of lanthanum, neodymium, and yttrium, B represents iron or a combination of iron and aluminum, C represents one or more elements selected from the group consisting of iridium, ruthenium, tantalum, niobium, molybdenum, and tungsten, &#x3b1; and &#x3b2; each represents a numerical value within a range of more than 0 and less than 1, and &#x3b1; and &#x3b2; satisfy relational formulae of &#x3b2;&#x3e;&#x3b1; and &#x3b1;+&#x3b2;&#x2266;1.

The exhaust gas-purifying catalyst of the invention contains oxide particles having interdispersed therein A crystallites that are loaded with a noble metal and B crystallites that are not loaded with a noble metal. The A crystallites loaded with a noble metal are composed of an oxide containing at least one of zirconium (Zr) and cerium (Ce). The B crystallites not loaded with a noble metal are composed of a cerium (Ce)-containing oxide which has a higher Ce content (mol %) than the oxide making up the A crystallites. The oxide particles have a specific surface area after 5 hours of heat treatment at 1,150&#xb0; C. in open air of 30 m/g or more.

Exhaust gas purifying catalyst

The exhaust gas purifying catalyst presented here includes a substrate and a catalyst coat layer formed on the surface of the substrate. The catalyst coat layer is formed in a laminate structure having two layers, with a first layer being nearer to the surface of the substrate and a second layer being relatively further from this surface. The second layer includes a carrier and a noble metal supported on the carrier. The first layer is a noble metal-free layer that does not contain a noble metal but does contain an OSC material having oxygen storage capacity.

An exhaust gas-purifying catalyst material includes first oxide particles having an average particle diameter Dof 1 &#x3bc;m to 95 &#x3bc;m and having an oxygen storage capacity, second oxide particles having an average particle diameter Dof 0.05 &#x3bc;m to 0.5 &#x3bc;m, containing a metal element, and having no oxygen storage capacity, precious metal particles, and acidic oxide particles. The material has a correlation coefficient &#x3c1; of 0.45 or more obtained using first characteristic X-ray intensity for the metal element contained in the second oxide particle, second characteristic X-ray intensity for an element other than oxygen contained in the acidic oxide particle, and third characteristic X-ray intensity for a precious metal element contained in the precious metal particle.

Exhaust gas-purifying catalyst and exhaust gas-purifying catalyst material

The exhaust gas-purifying catalyst of the invention includes a noble metal, and crystallites that form CZ composite metal particles which serve as a carrier supporting the noble metal and contain at least zirconium (Zr) and cerium (Ce). The CZ composite oxide particles (crystallites) further contain crystal growth-suppressing fine particles which are fine metal particles comprising primarily a metallic element M that melts at 1,500&#xb0; C. or above and which suppress crystal growth by the CZ composite oxide particles. The content of the metallic element M included in the CZ composite oxide particles, expressed in terms of the oxide thereof, is 0.5 mol % or less of the total oxide.

Provided is an exhaust catalyst that exhibits higher NO-reducing activities at the time of engine restart while maintaining its catalytic activities during normal traveling. This invention provides an exhaust cleaning catalyst comprising a substrate and a catalyst coating layer that includes CeO. Catalyst coating layer is constituted in its thickness direction with multiple coating layers. In a top coating layer located at the outermost surface, the CeOcontent in a top coating layer's upstream portion is less than the CeOcontent in a top coating layer's downstream portion; and the CeOcontent in the top coating layer's upstream portion is less than the CeOcontent in a lower coating layer. The CeOcontent per liter of catalyst volume in the entire coating layer is 10 g/L to 30 g/L.

Exhaust cleaning catalyst

Provided is an exhaust cleaning catalyst that exhibits higher NO-reducing activities at the time of engine restart while maintaining its catalytic activities during normal traveling. This invention provides an exhaust cleaning catalyst including a substrate and a catalyst coating layer including CeO. Catalyst coating layer is constituted in its thickness direction with multiple coating layers. In a top coating layer located at the outermost surface, the CeOcontent in a top coating layer's upstream portion is less than the CeOcontent in a top coating layer's downstream portion. In a bottom coating layer near substrate, the CeOcontent in a bottom layer's downstream portion is less than the CeOcontent in a bottom coating layer's upstream portion.

An exhaust cleaning catalyst, with which precious metal sintering is inhibited and which has greater exhaust cleaning abilities, has a substrate and a catalyst coating layer provided on the substrate. The catalyst coating layer has a precious metal that serves as an oxidation and/or reduction catalyst. The precious metal has Rh-containing metal particles in which rhodium (Rh) coexists with a base metal selected among platinum group elements excluding rhodium. The Rh-containing metal particles have an average rhodium content of 0.1% to 5% by mole with the total amount of the base metal and rhodium being 100% by mole.

Growing community of inventors

Kakegawa, Japan

Satoshi Matsueda