Cataler Corporation

Other

Daihatsu Motor Company, Ltd.

Hokko Chemical Industry Co., Ltd.

Yasunori Sato

Hirohisa Tanaka

Koichi Kasahara

Kenichi Taki

Keiichi Narita

Isao Tan

Nobuhiko Kajita

Mari Uenishi

Masashi Taniguchi

Noboru Sato

Koji Yamada

Mari Yamamoto

Tomohito Mizukami

Masaaki Kawai

Asuka Hori

Shigeji Matsumoto

Shinji Matsuura

Ichiro Takahashi

To provide a method for industrially efficiently producing an exhaust gas purifying catalyst containing a perovskite-type composite oxide which is stable and has a less reduced specific surface area and is also effectively prevented from decreasing in its catalytic performance even in endurance in high temperature oxidative reducing atmospheres, a pre-crystallization composition containing elementary components constituting a perovskite-type composite oxide containing a noble metal is prepared, is mixed with a powder of theta-alumina and/or alpha-alumina to prepare a mixture, and the mixture is heat treated. Thus, the resulting perovskite-type composite oxide supported by the powder of theta-alumina and/or alpha-alumina can keep its thermostability at a sufficient level thereby to effectively prevent the catalytic performance from decreasing. This method can industrially efficiently produce the exhaust gas purifying catalyst.

Method for producing exhaust gas purifying catalyst

An exhaust gas-purifying catalyst system is provided with a plurality of catalyst layers including a first and a second catalyst layers, supported on a support structure. The first catalyst layer comes into contact with an exhaust gas stream firstly among the plurality of catalyst layers. The second catalyst layer is provided adjacent to the first catalyst layer. The first catalyst layer contains a first noble metal active component including rhodium, together with a powder of a barely soluble barium compound in an amount of 0.05 mol to 0.2 mol per volume in liter of the support structure. The second catalyst layer contains a second noble metal active component.

Exhaust gas-purifying catalyst system

An exhaust gas-purifying catalyst includes a zeolite and a perovskite composite oxide containing palladium placed at its B site.

Exhaust gas-purifying catalyst

To provide an exhaust gas purifying catalyst which can maintain the catalytic activity at a high level over a long time and can achieve satisfactory emission control performance, an exhaust gas purifying catalyst is prepared so as to contain a noble metal, a perovskite-type composite oxide represented by the following general formula (3), and theta-alumina and/or alpha-alumina:ABNO&#x2003;&#x2003;(3)wherein A represents at least one element selected from rare-earth elements and alkaline earth metals; B represents at least one element selected from Al and transition elements excluding rare-earth elements and noble metals; N represents a noble metal; and m represents an atomic ratio of N satisfying the following relation: 0&#x3c;m&#x3c;0.5.

Catalyst for clarifying exhaust gas

A catalyst for purifying exhaust gases exhibits not only effective purifying characteristics even in a low temperature range such as immediately after an engine starts but also high exhaust gas purifying ability. In the catalyst for purifying exhaust gases of a first aspect of the invention, HC adsorbed at low temperature are released at high temperature and the released HC are purified by a catalyst metal. This catalyst for purifying exhaust gases has an excellent advantage in purifying HC at low temperature as well as excellent exhaust gas purifying ability.

Catalyst for purifying exhaust gases

A catalyst for purifying an exhaust gas includes an upstream side catalyst and a downstream side catalyst. The upstream side catalyst is disposed on an upstream side with respect to an exhaust gas flow, and the downstream side catalyst is disposed on a downstream side with respect thereto. The upstream side catalyst includes a first loading layer, being composed of an alumina containing Ba and La at least, and a first noble metal, being held by the first loading layer and being at least one member selected from the group consisting of Pd, Pd and Rh and Pd and Pt. Alternatively, in addition to the aluminum, the first loading layer can be composed of Ce, a solid solution of Ce and Zr and a solid solution of Ce, Zr and Y in an amount as less as possible. The downstream side catalyst includes a second loading layer, being composed of at least one member selected from the group consisting of an alumina containing La, Ce, a solid solution of Ce and Zr and a solid solution of Ce, Zr and Y, and a second noble metal, being held by the second loading layer and being composed of at least one member selected from the group consisting of Pt, Pd and Rh.

Catalyst for purifying an exhaust gas

A catalyst for purifying exhaust gases, which enables the HC-purification performance to be further improved by suitably arranging an HC-adsorbent. The catalyst includes a coating layer which is composed of alumina and zeolite, and carries a noble metal. The weight ratio of alumina and zeolite in the coating layer ranges from 5:1 to 1:1. Zeolite adsorbs HC when exhaust gases are in a low temperature region, and HC desorbed from zeolite is oxidized and purified with the noble metal.

Catalyst for purifying exhaust gas

A catalytic converter for cleaning exhaust gas includes a heat-resistant support, and a catalytic coating formed on the heat-resistant support. The catalytic coating contains Pd-carrying particles of a cerium complex oxide, Pt & Rh-carrying particles of zirconium complex oxide, and particles of a heat-resistant inorganic oxide.

Catalytic converter for cleaning exhaust gas

A hydraulic drive system for bicycles and the like comprises a casing adapted for enclosing a hanger portion of the bicycle, planetary gear type speed up gears including a carrier integral with a crankshaft for increasing the number of rotations of the crankshaft, an eccentric cam assembly including an outer eccentric cam and an inner eccentric driven by a sun gear of the speed up gears and a variable displacement hydraulic pump having plungers driven by the cam assembly and provided at an input portion of the driving system, the speed up gears, the eccentric cam assembly and the variable displacement hydraulic pump being housed in the casing.

Hydraulic drive system for bicycles and the like

A two-wheeled vehicle such as a bicycle includes a variable displacement fluid pump such as a radial plunger pump provided at a crankshaft of pedals and a fixed displacement fluid motor such as a gear motor at a rear wheel or a front wheel. The fluid pump and motor are connected through hydraulic passages. Plungers of the radial plunger pump are driven by a cam assembly whose eccentricity is adjustable by means of an eccentricity control means dependent upon the load acting upon the vehicle in a stepless manner, so that the speed of the vehicle can be changed in a stepless manner. Moreover, the vehicle includes automatic speed change means which automatically change the eccentricity of the eccentric cam assembly according to hydraulic pressure of the variable displacement fluid pump, so that the speed of the vehicle can be automatically changed.

Growing community of inventors

Ogasa-gun, Japan

Yasunori Sato