Mazda Motor Corporation

Madza Motor Corporation

Sanken Sangyo Kabushiki Kaisha

Kenji Okamoto

Hiroshi Yamada

Akihide Takami

Hideharu Iwakuni

Koichiro Harada

Makoto Kyogoku

Kenji Suzuki

Hiroshi Murakami

Kenichi Yamamoto

Seiji Miyoshi

Hirosuke Sumida

Takahiro Kurokawa

Junichi Taga

Masahiko Shigetsu

Youichi Kuji

Masayuki Kuroki

Yuki Koda

Makoto Kyougoku

Akihide Tamani

Hiroshi Yoshimura

Hirofumi Nishimura

Tomomi Watanabe

Tadataka Nakazumi

Mitsutoshi Abe

Takashi Takemoto

Toshiyuki Kikuchi

Kazuya Yokota

Hisaya Kawabata

Toshitsugu Ueoka

Satoshi Ichikawa

Kazuo Misonoo

Shinichi Tanioka

Taeko Shimizu

Hiroyuki Takebayashi

Yoshinori Tsushio

Osamu Takayama

Susumu Mineoi

Yuki Kooda

Akihida Takami

Kaori Imada

Katsuhiro Momii

Yuji Oota

Hiroki Fujita

In at least part of a catalyst layer of a particulate filter, a second catalyst part is exposed on the surface of the catalyst layer to overlie a first catalyst part, the first catalyst part contains Pt-carried activated alumina particles, the second catalyst part contains ZrNd-based mixed oxide particles containing a rare earth metal M and at least one of the first catalyst part and the second catalyst part further contains CeZr-based mixed oxide particles containing a rare earth metal R.

Catalyst-supported particulate filter

A catalyst layer formed on the walls of exhaust gas channels in a particulate filter contains a catalyst material containing at least two kinds of primary particles selected from the group consisting of primary particles of activated alumina, primary particles of a ZrNd-based mixed oxide and primary particles of a CeZr-based mixed oxide. The catalyst material is formed so that primary particles of one of the ZrNd-based mixed oxide and the CeZr-based mixed oxide are dispersedly carried on the surface of each of secondary particles. Each secondary particle is formed by cohesion of at least one kind of primary particles selected from the group consisting of primary particles of activated alumina and primary particles of the other of the ZrNd-based mixed oxide and the CeZr-based mixed oxide.

Disclosed is a particulate filter, which comprises a filter bodyincluding a plurality of filter segments F, Fjoined to each other by a joining material, wherein each of the filter segments includes a plurality of inflow cells each having a closed end on a downstream side in an exhaust-gas flow direction, and a plurality of outflow cells each having a closed end on an upstream side in the exhaust-gas flow direction. The filter segments include a first filter segment located in a central region of the particulate filter and designed to form each of the inflow cells to have an opening area approximately equal to that of each of the outflow cells, and a second filer segment located in at least a part of an outer peripheral region of the particulate filter and designed to form each of the inflow cells to have an opening area greater than that of each of the outflow cells. The present invention can keep the central region of the particulate filter from becoming overheated during a particulate-filter regeneration process, while suppressing a pressure loss.

Particulate filter

Disclosed is a catalytic material for purifying an exhaust gas component. The catalytic material comprises a composite oxide which contains, as essential components, zirconium (Zr) and neodymium (Nd), and further contains a rare-earth metal R other than cerium (Ce) and neodymium (Nd), wherein each of the zirconium, neodymium and rare-earth metal R constituting the composite oxide is contained, in the form of oxide, in such a manner that a ratio of NdO/(ZrO+NdO+RO) is 3 mol % or more, and a ratio of (NdO+RO)/(ZrO+NdO+RO) is 33 mol % or less. The catalytic material of the present invention can oxidize/burn PM in a short period of time, while suppressing CO emission during the burning of the PM, and can achieve further enhanced NOx conversion performance.

Catalytic material and catalyst for purifying exhaust gas component

In a particulate filter, a catalyst layer containing Pt-carried activated alumina particles, CeZr-based mixed oxide particles and ZrNd-based mixed oxide particles is formed, the proportion of the total amount of the CeZr-based mixed oxide particles and the ZrNd-based mixed oxide particles in the total amount of the Pt-carried activated alumina particles, the CeZr-based mixed oxide particles and the ZrNd-based mixed oxide particles is 10% to 60% by mass, both inclusive, and the mass ratio of the CeZr-based mixed oxide particles to the ZrNd-based mixed oxide particles is 20/80 to 80/20, both inclusive. This configuration enhances the particulate burning property and the low-temperature exhaust gas conversion efficiency.

Disclosed is a particulate filter, which is adapted to be disposed in an exhaust passage of an engine to trap particulate matter contained in exhaust gas discharged from the engine. The particulate filter comprises a filter body having a porous partition wall which defines a plurality of exhaust gas channels allowing the exhaust gas to pass therethrough, and a catalyst layer formed on a surface of the porous partition wall. The catalyst layer includes a Zr-based composite oxide which contains zirconium (Zr), and a rare-earth metal except cerium, wherein a content ratio of an oxide of the non-cerium rare-earth metal to a total amount of ZrOand the oxide of the non-cerium rare-earth metal in the Zr-based composite oxide is set in the range of greater than 33 mol % to less than 40 mol %. The particulate filter of the present invention can achieve a higher PM burning rate to burn PM within a shorter period of time. In addition, the higher PM burning rate makes it possible to provide enhanced fuel economy performance in an engine designed to perform a post-injection control.

A catalyst comprises an HC trapping material that is capable of trapping HC in an exhaust gas under low temperatures and releasing HC with a raise in temperature and catalytic material containing a Ce&#x2014;Pr double oxide capable of oxidizing and purifying HC from the HC trapping material with a high efficiency.

Exhaust gas purifying catalyst

The present invention provides a catalyst for purifying an exhaust gas having excellent heat resistance and a small level of deterioration of the purifying ability of the exhaust gas even if the catalyst is exposed to a high temperature atmosphere for a long time. The catalyst for purifying an exhaust gas comprises a catalytic metal for oxidizing HC and CO and reducing NO for purification, and a mixed oxide containing Ce, Zr and Sr.

Catalyst for purifying exhaust gas and method for purifying exhaust gas with the catalyst

A catalyst for lowering NOx concentration in an exhaust gas is disposed in an exhaust gas passage of an engine. The catalyst composed of a catalyst layer formed on a substrate. A NOx absorber that absorbs NOx when an oxygen concentration in the exhaust gas is high and releases NOx when the oxygen concentration drops, and a precious metal for reducing NOx are supported on a support material as catalyst components, and the NOx absorber includes Ba, K, Sr, and Mg. By lowering the oxygen concentration in the exhaust gas and raising a temperature of the NOx absorber when sulfur component is absorbed excessively in the NOx absorber, it is possible to regenerate the catalyst from the S poisoning.

Device for purifying exhaust gas, method for purifying exhaust gas, catalyst for purifying exhaust gas, and method for manufacturing exhaust gas purifying catalyst

An exhaust gas emission control catalyst includes an under catalyst layer containing at least one of barium and lanthanum and an over catalyst layer containing an agent for absorbing water in a gas, at least one of the under catalyst layer and over catalyst layer containing catalytic metal.

Burned gas purifying catalyst

An engine control device, which is adapted for an engine provided with an NOx-absorbing material arranged in an exhaust passage for absorbing NOx in an oxygen-rich atmosphere, and releasing NOx and absorbing sulfur content when the oxygen concentration drops, includes a discriminator for judging whether the amount of sulfur absorbed by the NOx-absorbing material has reached a prescribed quantity, and a reductant concentration controller which increases the temperature of the NOx-absorbing material by decreasing a quantity related to EGR ratio for desulfurizing the NOx-absorbing material based on the result of judgment made by the discriminator. When the quantity related to the EGR ratio is decreased, the temperature of exhaust gas increases. Consequently, the temperature of the NOx-absorbing material increases and the sulfur in the NOx-absorbing material is freed and released.

Engine control device

An exhaust gas purifying catalyst is provided by coating a slurry of a mixture of a powdered first catalyst provided by carrying Pt on a mixture of alumina and ceria and a powdered second catalyst provided by carrying Rh on manganese oxide on a support member and then impregnating the coated layer with a solution of barium.

Catalyst for purifying exhaust gas and manufacturing method thereof

An exhaust gas purifying system includes an exhaust gas purifying catalyst having a nitrogen oxide absorbing material which is installed in an exhaust line of an engine and performs split fuel injection to inject fuel directly into each combustion chamber partly during a suction stroke and partly during a compression stroke to provide and supply an increased amount of carbon monoxide to the nitrogen oxide absorbing material so as thereby to desorb sulfur oxides from the nitrogen oxide absorbing material.

Exhaust gas purifying system for engine

In the exhaust gas purifying catalyst (3), palladium is contained as a catalytic component and cerium oxide and (Ce, Pr) compound oxide is contained as a promoter. Now, the weight ratio of cerium oxide to (Ce, Pr) compound oxide is set between 9/1 and 7/3, and the ratio of praseodymium to cerium in the (Ce, Pr) compound oxide is set between 3 mol % and 50 mol %. In this way, because in this exhaust gas purifying catalyst (3), palladium with high low-temperature activity is used for a catalytic component, the exhaust gas purifying performance at low temperature is improved. And because cerium oxide and (Ce, Pr) compound oxide improves catalytic activity of palladium at high temperature, the exhaust gas purifying performance at high temperature, in particular, NOx purifying performance, is improved.

Catalyst for cleaning exhaust gas

A catalyst has a base catalyst layer containing platinum and barium as precious metal supported by alumina and an over catalyst layer containing platinum and rhodium as precious metal supported by zeolitr. The platinum and rhodium in the over catalyst layer activate NOx and HC so as to make them more reactive in terms of energy, and the barium in the base catalyst layer makes the platinum be more dispersive in the base catalyst layer. Under the existence of dispersive platinum, NOx in exhaust gas is decomposed and purified by reaction with reactive NO.sub.2 and partially oxidized HC generated in the over catalyst layer.

Growing community of inventors

Hiroshima, Japan

Kenji Okamoto