Nissan Motor Company Limited

Renault S.a.s.

Renault S.a.s. Societe Par Actions Simplifiee

Hironori Wakamatsu

Masanori Nakamura

Katsuo Suga

Kazuyuki Shiratori

Tetsuro Naito

Hirofumi Yasuda

Hiroto Kikuchi

Jun Ikezawa

Toru Sekiba

Toshiharu Miyamura

Junji Ito

Yasunari Hanaki

Maki Shimada

Makoto Aoyama

Misaki Akaishi

Hiroshi Akama

Masahiro Takaya

Motohisa Kamijo

Yoshiaki Hiramoto

Hideaki Morisaka

Kenji Uesugi

Masato Nagata

Masanori Nakamaura

Naito Tetsuro

An exhaust gas purification catalyst contains a first catalyst in which an oxide of general formula (1): LaMM'O(where La is lanthanum, M is at least one selected from a group consisting of barium (Ba), strontium (Sr) and calcium (Ca), M&#x2032; is at least one selected from a group consisting of iron (Fe), cobalt (Co), nickel (Ni) and manganese (Mn), &#x3b4; is the amount of oxygen defect, and x and &#x3b4; satisfy 0&#x3c;x&#x2266;1 and 0&#x2266;&#x3b4;&#x2266;1) is supported by an oxide capable of occluding and releasing oxygen, and a second catalyst containing a noble metal. The particle size of the oxide capable of occluding and releasing oxygen is within the range from 1 to 50 nm. The particle size of the oxide of the general formula (1) is within the range from 1 to 30 nm.

Exhaust gas purification catalyst, exhaust gas purification monolith catalyst, and method for producing exhaust gas purification catalyst

An exhaust gas purifying catalyst having a high purifying ability even if noble metal is not used as an essential component, an exhaust gas purifying monolith catalyst, and a method for manufacturing an exhaust gas purifying catalyst, are provided. The exhaust gas purifying catalyst includes an oxide having an oxygen storage and release capacity, and an oxide represented by the following formula (1) supported on the oxide having the oxygen storage and release capacity,LaMM'O&#x2003;&#x2003;(1)(wherein La represents lanthanum, M represents at least one element selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca), M&#x2032; represents at least one element selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni) and manganese (Mn), &#x3b4; represents an oxygen deficient amount, and x and &#x3b4; fulfill conditions represented by 0&#x3c;x&#x2266;1 and 0&#x2266;&#x3b4;&#x2266;1, respectively).

Exhaust gas purifying catalyst, exhaust gas purifying monolith catalyst, and method for manufacturing exhaust gas purifying catalyst

The present invention provides an exhaust gas purifying catalyst that can keep high catalytic performance even being subjected to exhaust gas. The exhaust gas purifying catalyst includes: noble metal particles (); and supports (), each support supporting the noble metal particles (), wherein at least a certain amount of the noble metal particles () is provided on an outermost surface of the support (), or provided within a range of 10% inside of a diameter of the support () from the outermost surface in a direction toward a center of the support.

Exhaust gas purifying catalyst

An object is to maintain an effect of enhancing activity of noble metal particles by transition metal without increasing production cost and an environmental load. An exhaust gas purifying catalystis composed of: noble metal particles; first compoundswhich contact the noble metal particlesand suppress movement of the noble metal particles; and second compoundswhich contain the noble metal particlesand the first compounds, suppress the movement of the noble metal particles, and suppress coagulation of the first compoundsfollowing mutual contact of the first compounds, wherein the first compoundssupport the noble metal particles, and simplexes or aggregates of the first compoundssupporting the noble metal particlesare included in section partitioned by the second compounds

Exhaust gas purifying catalyst and production method thereof

An exhaust gas purifying catalyst includes: a catalyst particle unit having at least noble metal with a catalytic function, first oxides on which the catalyst noble metal is supported, and second oxides covering the first oxides on which the noble metal is supported. In catalyst powder formed of an aggregate of plural pieces of the catalyst particle units, at least one type of compounds selected from the group consisting of a transition element, an alkali earth metal element, an alkali metal element, and a rare earth element, which is a promoter component, are contained.

Exhaust gas purifying catalyst and producing method thereof

An exhaust gas purifying catalyst is constituted by: noble metal particles (); first compounds () which support the noble metal particles (); second compounds () different in type from the first compounds (); and oxides () which surround the noble metal particles (), the first compounds () and the second compounds (). A median diameter of the first compounds () and a median diameter of the second compounds () satisfy a relationship of a following inequality:median diameter of first compounds&#x3c;median diameter of second compounds.

An exhaust gas purifying catalyst includes: rhodium; a zirconium-containing oxide which supports rhodium, and comprises: at least one element selected from the group consisting of calcium, lanthanum, cerium, neodymium and yttrium; and zirconium; and a NOx absorbing material comprising at least one selected from the group consisting of magnesium, barium, sodium, potassium and cesium. A degree of dispersion of rhodium is 20% or more after baking at 900&#xb0; C. in air for three hours. A method for manufacturing the exhaust gas purifying catalyst includes: mixing the zirconium-containing oxide with water, thereby preparing an aqueous liquid of the zirconium-containing oxide; and supporting rhodium on the zirconium-containing oxide by mixing the aqueous liquid of the zirconium-containing oxide with an aqueous solution of a rhodium salt. A pH of a mixed liquid of the aqueous solution of the rhodium salt and the aqueous liquid of the zirconium-containing oxide is adjusted to 7 or more.

Exhaust gas purifying catalyst and method for manufacturing the same

An exhaust gas purifying catalyst () according to the present invention includes noble metal particles (), a first compound () supporting the noble metal particles (), and a second compound () disposed not in contact with the noble metal particles () and having an oxygen storage capacity. An average distance between the first compound () and the second compound () is between 5 nm and 300 nm.

An exhaust gas purifying catalyst includes a monolithic substrate (), and a transition metal oxide layer () formed in the monolithic substrate (). The transition metal oxide layer () contains transition metal oxide powder including: transition metal oxide particles (); a first compound () on which the transition metal oxide particles () are supported; and a second compound () that surrounds a single body or an aggregate of the transition metal oxide particles () and the first compound ().

An exhaust gas purifying catalyst () is composed of: a noble metal (); a first compound (); and a second compound (). The noble metal () is supported on the first compound (). The exhaust gas purifying catalyst () includes units having a structure in which the first compound () supporting the noble metal () is surrounded by the second compound (), and the first compound () supporting the noble metal () is isolated from one another by the second compound (). The noble metal () is one or more selected from [Pt, Pd and Rh], the first compound () contains Ti as a main component, and the second compound () contains, as a main component, one or more selected from [Al and Si].

Exhaust gas purifying catalyst and method for producing the same

A high heat-resistant catalyst includes: noble metal particles; first compounds which contact the noble metal particles and suppress movement of the noble metal particles; and second compounds which envelop the noble metal particles and the first compounds, suppress the movement of the noble metal particles, and suppress coagulation of the first compounds following mutual contact of the first compounds. The first compounds support the noble metal particles, and single piece or aggregate of the first compounds supporting the noble metal particles are included in a section partitioned by the second compounds. A coefficient of linear thermal expansion of the second compounds is 1.2&#xd7;10[K] or less.

High heat-resistant catalyst and manufacturing method thereof

Disclosed is an exhaust gas purifying catalyst exhibiting excellent purification performance for a long period of time by suppressing coagulation of a noble metal. A catalyst powder comprises a noble metal and first and second compounds. In the catalyst powder, the first compound carries the noble metal and is separated from another first compound carrying a noble metal by the second compound. At least one catalyst layer comprising the catalyst powder is formed on an inner surface of a substrate. The catalyst layer has fine pores. A fine pore volume of fine pores having a fine pore diameter of greater than 0.1 &#x3bc;m to less than or equal to 1 &#x3bc;m is 10% to 60% of the fine pore volume of fine pores having a pore diameter of 1.0 &#x3bc;m or less.

Exhaust gas purifying catalyst and method of producing the same

An exhaust gas purifying catalyst that includes noble metal particles, first compounds which support the noble metal particles and suppress movement of the noble metal particles, and second compounds which encapsulate the noble metal particles and the first compounds. The second compounds suppress the movement of the noble metal particles and suppress coagulation of the first compounds following mutual contact of the first compounds.

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Yokohama, Japan

Hironori Wakamatsu