Cataler Corporation

Toyota Jidosha Kabushiki Kaisha

Ichiro Kitamura

Kenichi Taki

Akimasa Hirai

Norihisa Nakagawa

Shuntaro Okazaki

Takahiko Fujiwara

Ryota Onoe

Naoto Miyoshi

Koji Morita

Keiichi Narita

Masahiko Takeuchi

Akemi Sato

Yasutaka Nomura

Hiroshi Sekine

Keisuke Nagasaka

Atsushi Tanaka

Yuta Morishita

Daisuke Ochiai

Junji Kuriyama

Akihito Inoue

Jun Sawada

Kouichi Kimura

Satoshi Kamitani

Provided is an exhaust gas purification catalyst that combines reduction of pressure loss and enhancement of purification performance. This invention provides an exhaust gas purification catalyst comprising a wall-flow-type substrate and first and second catalytic layers. The first catalytic layer is provided to the interior of a partition wall, in contact with an entrance cell, from an exhaust inlet-side end in the running direction, having a length Lless than Lw. The second catalytic layer is provided to the interior of a partition wall, in contact with an exit cell, from an exhaust outlet-side end in the running direction, having a length Lless than Lw. An internal portion of partition wall in contact with entrance cell has a substrate-exposing segment near the exhaust outlet-side end.

Exhaust gas purification catalyst

An exhaust gas control apparatus for an internal combustion engine, controls an exhaust operation of the internal combustion engine () provided with an exhaust gas purification catalyst () in an exhaust passage (). The exhaust gas control apparatus for the internal combustion engine is provided with; a warming-up device configured to warm up the exhaust gas purification catalyst; and an oxygen supplying device () configured to supply oxygen to the exhaust gas purification catalyst after the end of the warm-up. This makes it possible to preferably desorb sulfur adsorbed to the exhaust gas purification catalyst during warm-up. It is therefore possible to suppress a reduction in purification ability of the exhaust gas purification catalyst due to sulfur coating.

Exhaust gas control apparatus for internal combustion engine

Provided is an exhaust gas-purifying catalyst excelling in an exhaust gas-purifying performance. The exhaust gas-purifying catalyst contains a substrate, and a catalyst layer formed on the substrate and containing a precious metal and praseodymium.

Exhaust gas-purifying catalyst

An exhaust gas purifying catalyst includes a catalyst substrate and a catalyst coating layer containing a noble metal and a refractory inorganic oxide. The catalyst coating layer includes an upstream portion located upstream and a downstream portion located downstream in a flow direction of an exhaust gas. The upstream portion has a layered structure including an upstream portion inside layer containing a cerium-zirconium composite oxide in which a relative proportion of CeOis 50 to 95 wt %, as the refractory inorganic oxide and an upstream portion outside layer containing a cerium-zirconium composite oxide in which a relative proportion of ZrOis 50 to 95 wt %, as the refractory inorganic oxide. The upstream portion outside layer and the downstream portion contain Rh as the noble metal, and an amount of Rh contained in the upstream portion outside layer is larger than an amount of Rh contained in the downstream portion.

Exhaust gas purifying catalyst

An exhaust gas purifying catalyst is provided which includes a catalyst substrate and a catalyst coating layer. The catalyst coating layer is formed on the catalyst substrate and contains a noble metal and a refractory inorganic oxide. The catalyst coating layer has a layered structure including an A-layer and a B-layer. The A-layer contains Pd and Pt as the noble metal in a weight ratio of 3:1 to 20:1. The B-layer includes Rh as the noble metal.

A high exhaust gas-purifying performance is achieved. An exhaust gas-purifying catalyst includes a substrate, a lower layer covering the substrate and including an oxygen storage material and palladium, and an upper layer covering the lower layer and including rhodium and a carrier supporting it. The lower layer is rhodium-free. The upper layer has an oxygen storage capacity lower than that of the lower layer.

An exhaust gas purifying catalyst having a good ignition performance is provided. The exhaust gas purifying catalystincludes a catalyst substrateand a catalyst coating layerwhich contains a noble metal and a refractory inorganic oxide and is formed on the catalyst substrate. The exhaust gas purifying catalyst is characterized in that the catalyst coating layerincludes an upstream portionlocated upstream and a downstream portionlocated downstream in a flow direction of an exhaust gas. The upstream portionhas a layered structure including an upstream portion inside layerand an upstream portion outside layer. The upstream portion inside layer contains a cerium-zirconium composite oxide in which a relative proportion of CeOis 50 to 95 wt %, as the refractory inorganic oxide, and the upstream portion outside layerand the downstream portioncontain a cerium-zirconium composite oxide in which a relative proportion of ZrOis 50 to 95 wt %, as the refractory inorganic oxide.

This is to provide a catalyst for purifying exhaust gases, catalyst which are good in terms of the purifying performance. A catalyst according to the present invention for purifying exhaust gases comprises: a catalytic support substrate (); a first catalytic layer () having a first loading layer formed on an upstream side of the catalytic support substrate () and made of a fire-resistant inorganic oxide, and Rh loaded in the first loading layer; a second catalytic layer () having a second loading layer formed on a surface of the catalytic support substrate () on an downstream side of the first catalytic layer () and made of a fire-resistant inorganic oxide, and Pd and/or Pt loaded in the second loading layer; and a third catalytic layer () having a third loading layer formed on a surface of the second catalytic layer () and made of a fire-resistant inorganic oxide, and Rh loaded in the third loading layer; and is characterized in that: the first catalytic layer () is such that, when taking Rh loaded in the first catalytic layer as 100% by weight, Rh is loaded in an amount of 70% by weight or more within such a range that the distance from the surface is 20 &#x3bc;m; and the loading amount of Rh loaded in the first catalytic layer () is from 1.5 to 15 times as much as the loading amount of Rh loaded in the third loading layer. Because of the fact that Rh is loaded in a great loading amount in the superficial layer portion on an upstream side of exhaust-gas flow, it turns into a catalyst for purifying exhaust gases, catalyst which is good in terms of the purifying characteristics.

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Kakegawa, Japan

Ichiro Kitamura