Kabushiki Kaisha Toyota Chuo Kenkyusho

Toyota Jidosha Kabushiki Kaisha

Cataler Corporation

The University of Tokyo

Miho Hatanaka

Naoki Takahashi

Akihiko Suda

Akira Morikawa

Toshitaka Tanabe

Toshio Yamamoto

Masahide Miura

Yuki Aoki

Toshiyuki Tanaka

Takeru Yoshida

Nobuyuki Takagi

Yasutaka Nagai

Yasuo Ikeda

Kazuhiko Dohmae

Yusuke Akimoto

Naohiro Terao

Masaoki Iwasaki

Shinichi Matsumoto

Hideo Sobukawa

Yoshinori Saito

Masaya Ibe

Shingo Sakagami

Takao Tani

Kiyoshi Yamazaki

Toshio Kandori

Masaru Ogura

Takahiro Hayashi

Masaaki Kawai

Taizo Yoshinaga

Haruo Imagawa

Naoki Kumatani

Chika Ando

A catalyst for purification of exhaust gas in which Pd-based nanoparticles and ceria nanoparticles are supported on a composite metal oxide support containing alumina, ceria, and zirconia, wherein a molar ratio (Ce/Pd) of Ce and Pd supported on the support is 1 to 8, a proximity α between Pd and Ce is 0.15 to 0.50, wherein the proximity α is determined, based on Pd and Ce distribution maps in an element mapping image of energy dispersive X-ray analysis, by the following formula (1): a Pd dispersity after a heat-resistance test at 1050° C. for 25 hours is 0.8% or more.

Catalyst for purification of exhaust gas and production method thereof

An oxygen storage/release material includes: a ceria-zirconia composite oxide porous body that has at least one ordered phase of a pyrochlore phase and a &#x3ba; phase, and that has a central pore diameter of 70 nm to 1 &#x3bc;m as measured by a mercury penetration method, and in which a cumulative pore volume of pores that each have a pore diameter in the range of 0.5 times to 2 times the central pore diameter is 40% or more of the cumulative pore volume of pores that each have a pore diameter in the range of 10 nm to 10 &#x3bc;m as measured by the mercury penetration method.

Oxygen storage/release material

A catalyst for purification of exhaust gas, comprising a first catalyst comprising:

Catalyst for purification of exhaust gas, NOx storage-reduction catalyst, and method for purifying exhaust gas

A method for producing iron-supporting chabazite-type zeolite, comprising the following steps in order: mixing iron(II) chloride and chabazite-type zeolite, heat treating under a reducing atmosphere, and a Hydrogen reducing.

Method for producing exhaust gas purification catalyst

An exhaust gas purification catalyst includes a composite oxide support, and a precious metal catalyst supported on the composite oxide support. The composite oxide support includes alumina, zirconia, ceria, a first additive element oxide and a second additive element oxide. The first additive element oxide contains an additive element selected from the group consisting of rare earth elements excluding cerium and alkali earth elements. The second additive element oxide contains an additive element selected from the group consisting of rare earth elements excluding cerium and alkali earth elements. In the composite oxide support, alumina is contained in a range of 30 to 40% by mass and zirconia is contained in a range of 36 to 46% by mass.

Exhaust gas purification catalyst

An exhaust gas purifying catalyst includes a substrate that defines an exhaust gas passage; a lower catalyst layer formed over the substrate, and an upper catalyst layer formed over the lower catalyst layer. The lower catalyst layer 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 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 includes 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 and alkaline earth elements. The Nd is unevenly distributed in covering layers that covers surfaces of interior regions within the inorganic mixed oxide.

Exhaust gas purifying catalyst

An exhaust gas purification system includes: a catalyst () provided in an exhaust gas passage of an internal combustion engine () and having a carrier containing a basic oxide and platinum carried on the carrier; a catalyst () for purifying NOx; and oxygen supply means ().

Exhaust gas purification system for internal combustion engine

A catalyst for purification of exhaust gas in which a noble metal is supported on a metal-oxide support wherein, in a oxidation atmosphere, the noble metal exists on the surface of the support in high oxidation state, and the noble metal binds with a cation of the support via an oxygen atom on the surface of the support to form a surface oxide layer and, in a reduction atmosphere, the noble metal exists on the surface of the support in a metal state, and an amount of noble metal exposed at the surface of the support, measured by CO chemisorption, is 10% or more in atomic ratio to a whole amount of the noble metal supported on the support.

Catalyst for purification of exhaust gas, regeneration method for the catalyst, and apparatus and method for purification of exhaust gas using the catalyst

A particulate inorganic mixed oxide comprising: aluminum; zirconium; cerium; lanthanum and an additional element selected from the group consisting of neodymium and praseodymium, wherein the inorganic mixed oxide has at least 80% of primary particles with article diameters of 100 nm or less, and at least a part of the primary particles have an enriched surface region where the additional element is locally increased in a surface layer portion thereof.

Inorganic mixed oxide and catalyst for purification of exhaust gas using the same

This composite oxide powder can secure a large pore volume even after calcination at high temperature and, when a catalyst is formed by loading a noble metal on this composite oxide powder, noble metal grain growth can be suppressed. The composite oxide powder comprises particles of an oxide of a metal Mand an oxide of a metal Mwhich does not dissolve in the oxide of the metal M, the oxide of the metal Mand the oxide of the metal Mbeing dispersed at the nanometer level. Since different oxides serve as a barrier to each other, sintering is suppressed. Therefore, in the case of composite oxide powder comprising Ce as a metal Mand Al as a metal M, grain growth is small even after exposed to high temperature and pores of 3.5-100 nm secure a volume of 0.07 cc/g or more after calcination at 600&#xb0; C. for 5 hours and a volume of 0.04 cc/g or more after calcination at 800&#xb0; C. for 5 hours.

Composite oxide powder, a method for producing the same and a catalyst using the same

Disclosed are a porous material comprising particles without substantial fibrous structure and having pores, the pores having a mean pore diameter in a meson-pore region, sharp pore size distribution, and at least a part of the pores being connected three-dimensionally to form a three-dimensional network structure with random passages, the porous material preferably being of alumina and having a spongy structure or the porous material preferably being an aggregate of particles having an aspect ratio of 3 or less; a process of producing the porous material which includes a step of aging a system capable of becoming an oxide on thermal decomposition; a catalyst for exhaust gas purification having excellent NOremoval performance, high resistance against sulfur poisoning, and satisfactory high-temperature durability which comprises the porous material as a carrier having supported thereon a noble metal and an NOstorage component; and a method of exhaust gas purification using the catalyst.

Porous material process of producing the porous material, catalyst for purifying exhaust gas comprising the porous material, method of purifying exhaust gas

A composite oxide includes agglomerated particles which have an average particle diameter of 20 &#x3bc;m or less, which are composed of a plurality of metallic element oxides being in form of fine particles having an average diameter of 50 nm or less, and which have a surface and an inner portion whose metallic element distributions differ with each other. The characteristics of the respective metallic elements are exhibited maximally. Hence, it is extremely useful as a support for an exhaust gas purifying catalyst. The catalyst exhibits the activities which degrade less even after it is subjected to a sever durability, is good in terms of the heat and sulfur-poisoning resistance, and can efficiently purify the harmful components in exhaust gases. Moreover, it is possible to produce such a composite oxide and catalyst easily and stably by production processes disclosed herein.

Composite oxide, process for producing the same, catalyst for purifying exhaust gas, and process for producing the same

Composite oxide powder has a large specific surface area and a large pore volume even after a high-temperature durability test, without losing oxygen storage ability of a single metal oxide. In this composite oxide powder, a first metal oxide having oxygen storage ability is held as ultrafine particles in the form of islands by a second metal oxide which is different from the first metal oxide, pore volume is not less than 2 cc/g and the first metal oxide particles have a diameter of not more than 30 nm even after subjected to high temperature of 900&deg; C. or more. Since the first metal oxide particles are held in the form of islands by the second metal oxide particles, separated from each other and suppressed from contacting each other, the first metal oxide particles hardly grow granularly.

Composite oxide powder, catalyst and process for producing the same

Disclosed are a porous material comprising particles without substantial fibrous structure and having pores, the pores having a mean pore diameter in a meso-pore region, sharp pore size distribution, and at least a part of the pores being connected three-dimensionally to form a three-dimensional network structure with random passages, the porous material preferably being of alumina and having a spongy structure or the porous material preferably being an aggregate of particles having an aspect ratio of 3 or less; a process of producing the porous material which includes a step of aging a system capable of becoming an oxide on thermal decomposition; a catalyst for exhaust gas purification having excellent NO removal performance, high resistance against sulfur poisoning, and satisfactory high-temperature durability which comprises the porous material as a carrier having supported thereon a noble metal and an NO storage component; and a method of exhaust gas purification using the catalyst.

Porous material, catalyst, method of producing the porous material and method for purifying exhaust gas

Disclosed are (1) a titania-zirconia powder having at least a part of the zirconia solid-dissolved in the titania crystalline phase or at least a part of the titania solid-dissolved in the zirconia crystalline phase, (2) a titania-zirconia powder containing 3 to 30 wt % of zirconia and 0.5 to 10 wt % of yttria and containing less than 20 wt %, in total, of at least a complex oxide having a composition of ZrTiO or (Ti,Zr) O , monoclinic phase zirconia, and tetragonal phase zirconia, wherein the titania-zirconia powder comprises an anatase phase, and which retains a specific surface area of 34 m /g or more after heat-treated at 900&deg; C. for 5 hours in the air, and (3) a titania-zirconia powder wherein the titania-zirconia powder ( ) or ( ) having an average particle size of 1 &mgr;m or smaller is mutually dispersed with an alumina powder; and processes for producing the powders are disclosed.

Growing community of inventors

Nagakute, Japan

Miho Hatanaka