Toyota Jidosha Kabushiki Kaisha

Cataler Corporation

Kabushiki Kaisha Toyota Chuo Kenkyusho

Denso Corporation

Yuki Aoki

Hiromasa Suzuki

Takeru Yoshida

Toshitaka Tanabe

Hiroyuki Matsubara

Isao Chinzei

Yoshinori Saito

Naoki Takahashi

Akira Morikawa

Hirotaka Ori

Miho Hatanaka

Masahide Miura

Ryota Onoe

Akihiko Suda

Shingo Sakagami

Mitsuyoshi Okada

Masaaki Kawai

Oji Kuno

Naohiro Hayashi

Takeshi Nobukawa

Akiya Chiba

Daisuke Ochiai

Nobusuke Kabashima

Kosuke Iizuka

Yuki Naganuma

Hideaki Ueno

Masanao Sato

Tomoaki Sunada

Masahiro Nakahara

Singo Sakagami

The exhaust gas cleaning catalyst according is provided with a substrate and a catalyst coat layer formed on a surface of the substrate. The catalyst coat layer is formed as a laminate structure having an upper layer and a lower layer. The upper layer is a Pd-free layer that does not contain Pd, and the lower layer is a Pd-containing layer. In addition, when a region of the lower layer that corresponds to 20% of the length of the exhaust gas cleaning catalyst from the exhaust gas inlet side end towards the exhaust gas outlet side of the exhaust gas cleaning catalyst is divided into four equal regions to be each 5% of the length, the relationship A&#x3e;B&#x3e;C is satisfied, where A, B, and C represents the Pd content in the first, second, and third region respectively.

Exhaust gas cleaning catalyst

The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing HS emissions. The object is solved by an exhaust gas purifying catalyst in which the lower layer of the catalyst coating layer comprises a ceria-zirconia composite oxide having a pyrochlore-type ordered array structure, in which the ceria-zirconia composite oxide contains at least one additional element selected from the group consisting of praseodymium, lanthanum, and yttrium at 0.5 to 5.0 mol % in relation to the total cation amount, and the molar ratio of (cerium+additional element):(zirconium) is within the range from 43:57 to 48:52.

Exhaust gas purifying catalyst

The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing HS emissions. The object is solved by an exhaust gas purifying catalyst in which the top layer of a catalyst coating layer comprises a ceria-zirconia composite oxide having a pyrochlore-type ordered array structure, in which the ceria-zirconia composite oxide contains at least one additional element selected from the group consisting of praseodymium, lanthanum, and yttrium at 0.5 to 5.0 mol % in relation to the total cation amount, and the molar ratio of (cerium+additional element):(zirconium) is within the range from 43:57 to 48:52.

There is provided a catalytic converter that offers high exhaust gas cleaning performance by effectively utilizing a whole catalyst that constitutes the catalytic converter. In a catalytic converter (), catalytic layers (A,B) made of a noble metal catalyst are formed on cell wall surfaces of a substrate () having a cell structure, and the catalytic layers (A,B) extend in a longitudinal direction of the substrate () along which gas flows. The substrate () has a central region (A) having a relatively high cell density and a peripheral region (B) having a relatively low cell density. The length of each of the catalytic layers (B) in the longitudinal direction in the peripheral region (B) is longer than the length of each of the catalytic layers (A) in the longitudinal direction in the central region (A).

Catalytic converter

Provided is a catalytic converter capable of obtaining superior NOx purification performance while reducing the amount of a noble metal catalyst. A catalytic converterincludes: a substratehaving a cell structure in which exhaust gas flows; and catalyst layersthat are formed on cell wall surfacesof the substrate. The catalyst layersinclude a first catalyst layerdisposed on an upstream side of the substratein an exhaust gas flow direction and a second catalyst layerdisposed on a downstream side of the substrate in the exhaust gas flow direction. The first catalyst layeris formed of a support and rhodium which is a noble metal catalyst supported on the support. The second catalyst layeris formed of a support and palladium or platinum which is a noble metal catalyst supported on the support. The first catalyst layeris formed in a range of 80% to 100% of a total length of the substratestarting from an end of the substrate on the upstream side, and the second catalyst layeris formed in a range of 20% to 50% of the total length of the substratestarting from an end of the substrate on the downstream side.

A catalytic converter includes a substrate () and a catalyst layer (). The catalyst layer includes a bottom catalyst layer (), a first top catalyst layer () and a second top catalyst layer (). The second top catalyst layer is provided on a downstream side relative to the first top catalyst layer. The first top catalyst layer is made of a ceria-free zirconia composite oxide support and rhodium. The second top catalyst layer is made of a ceria-containing zirconia composite oxide support and rhodium. The first top catalyst layer has a length that is X % of the entire length of the substrate. The second top catalyst layer has a length that is 100&#x2212;X % of the entire length of the substrate. A ratio of a density of rhodium in the first top catalyst layer to a density of rhodium in the second top catalyst layer is at least 1 and at most 3.

An objective of the present invention is to provide a method for producing a catalyst for exhaust gas removal having excellent heat tolerance and purification performance within a wide range of atmospheres and a catalyst obtained by the production method. The present invention relates to a method for supporting catalyst metal particles, comprising: (a) adding an iridium precursor and a palladium precursor to a solvent containing at least one member selected from the group consisting of polyvinylpyrrolidone, N-methylpyrrolidone, N-vinyl-2-pyrrolidone, and ethylene glycol; (b) adding a reducing agent to the obtained catalyst metal colloid; (c) obtaining a concentrated solution containing catalyst metal particles by subjecting the obtained solution to heat reflux; and (d) supporting the catalyst metal particles on a carrier, wherein the iridium content of the catalyst metal particles accounts for 3% to 10% by mass of the total mass of iridium and palladium.

Method for producing catalyst for exhaust gas removal and catalyst obtained by the production method

A catalytic converter with excellent OSC performance and Nopurification performance. The catalytic converter includes a substrate with a cell structure and a catalyst layer formed on a cell wall surface of the substrate. The catalyst layer has a catalyst layer arranged on the upstream side and a catalyst layer arranged on the downstream side in an exhaust gas flow direction on the substrate. The catalyst layer on the upstream side includes a support containing an AlO&#x2014;CeO&#x2014;ZrOternary composite oxide (ACZ material) and an AlO&#x2014;ZrObinary composite oxide (AZ material), and at least Rh that is a noble metal catalyst carried on the support, and the catalyst layer on the downstream side includes a support and Pd or Pt that is a noble metal catalyst carried on the support. In the support in the catalyst layer on the upstream side, the mass proportion of ACZ material/(ACZ material+AZ material) is in the range of 0.33 to 0.5, and greater than or equal to 75% mass Rh is carried on the AlO&#x2014;ZrObinary composite oxide of the support.

A catalyst converter includes: a substrate () having a cell structure formed of a center area (A) having the highest cell density, a peripheral area (C) having the lowest cell density, and an intermediate area (B) having the cell density between that of the center area and that of the peripheral area; a first catalyst layer formed in the center area (A); a second catalyst layer formed in the intermediate area (B); and a third catalyst layer formed in the peripheral area (C). A length in a longitudinal direction of the second catalyst layer is longer than that of the first catalyst layer. A length in the longitudinal direction of the third catalyst layer is longer than that of the second catalyst layer. A ratio of the length in the longitudinal direction of the first catalyst layer to the length of the substrate is 65% or more.

Catalyst converter

Provide is a catalytic converter including a substrate which includes regions having different cell densities, in which exhaust gas purification performance is superior in all the regions of the substrate. A catalytic converterincludes catalyst layers in which a noble metal catalyst is supported on a support in surfaces of cell wallsof a substratehaving a cell structure in a longitudinal direction of the substratein which gas flows, in which the substratehas a first regionA having a relatively high cell density and a second regionB having a relatively low cell density, and a ratio of a thickness of a catalyst layerA in the second regionB to a thickness of a catalyst layerin the first regionA is in a range of more than 0.95 times and 1.2 times or less.

Provided is a catalytic converter in which the entire catalyst constituting the catalytic converter can be efficiently utilized to purify exhaust gas, and the emission of hydrogen sulfide can be suppressed. A catalytic converterincludes catalyst layersA,B formed of a noble metal catalyst that are formed on cell wall surfaces of a substratehaving a cell structure in a longitudinal direction of the substratein which gas flows, in which the substratehas a center regionA having a relatively high cell density and a peripheral regionB having a relatively low cell density, and lengths of the catalyst layersA,B of the center regionA and the peripheral regionB in the longitudinal direction are the same as each other, or the length of the catalyst layerB in the longitudinal direction is shorter than that of the catalyst layerA.

An object of the present invention is to provide an exhaust gas catalyst that can achieve high purification performance. The exhaust gas catalyst includes: a base material () having a plurality of inner wall surfaces () formed by a plurality of through holes () penetrating therethrough from a first end surface () to a second end surface (); and a plurality of catalyst layers () formed on the plurality of inner wall surfaces (), respectively, wherein: each of the through holes () has a central axis (X); each of the catalyst layers () is sectioned into a first region (A) extending from the first end surface () toward the second end surface () by a predetermined distance, a second region (B) extending from the second end surface () toward the first end surface () by a predetermined distance, and a third region (C) placed between the first region (A) and the second region (B); and the catalyst layer () is formed such that a distance (h) from the central axis (X) of the through hole () to an inner surface () of the catalyst layer () in the first region (A) of the catalyst layer () is smaller than a distance (h) from the central axis (X) of the through hole () to the inner surface () of the catalyst layer () in the third region (C) of the catalyst layer (), but is larger than a distance (h) from the central axis (X) of the through hole () to the inner surface () of the catalyst layer () in the second region (B).

Exhaust gas catalyst

A catalytic converter () includes a base material and a catalyst layer (). The catalyst layer has a lower catalyst layer () and an upper catalyst layer (). The upper catalyst layer is constituted by a first upper catalyst layer () and a second upper catalyst layer (). The first upper catalyst layer is formed of a first carrier, which is formed of a ceria-containing oxide, and rhodium supported on the first carrier. The second upper catalyst layer is formed of a second carrier and rhodium supported on the second carrier. The second carrier does not contain ceria and is formed of one oxide selected from among zirconia and alumina. A length of the first upper catalyst layer is X % (30 to 70%) of an overall length of the base material. A length of the second upper catalyst layer is 100&#x2212;X % of the overall length of the base material.

An exhaust gas purification catalyst is provided with a substrate and a catalyst coating layer formed on the surface of the substrate. The catalyst coating layer is formed into a layered structure having upper and lower layers, with a lower layer being closer to the surface of the substrate and an upper layer being relatively farther therefrom. The catalyst coating layer is provided with Rh and Pd as precious metal catalysts and is provided with an OSC material having an oxygen storage capacity as a support. The Rh is disposed in the upper layer of the catalyst coating layer, and the Pd is disposed in both the upper layer and the lower layer of the catalyst coating layer. At least a portion of the Pd in the upper layer and in the lower layer is supported on the OSC material. The mass ratio of the Pd disposed in the upper layer to the Pd disposed in the lower layer is not more than 0.4.

Exhaust gas purification catalyst

The exhaust gas purification apparatusaccording to the present invention is provided with an exhaust gas purification catalyst, an upstream Osensor, a downstream Osensor, and a control sectionthat executes main F/B control and sub-F/B control. This exhaust gas purification apparatuscontains, on a support in a prescribed regionfrom a catalyst-outlet-side endat the downstream side of an exhaust gas purification catalyst, an OSC material having a pyrochlore structure and an OSC material having an oxygen storage rate that is faster than that of the OSC material having a pyrochlore structure.

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Seto, Japan

Yuki Aoki