Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Kazuhide Terada

Takeshi Narishige

Yoshiyuki Nakanishi

Naohiro Satoh

Yoshikazu Fujisawa

Tomomi Sugiyama

Ken Ogawa

Toru Yano

Nobuhiro Saito

Kaoru Fukuda

Keizo Iwama

Masanobu Miki

Yuichi Matsuo

Kenji Dosaka

Hidehito Ikebe

Naohiro Satou

A system for purifying an exhaust gas includes a plasma unit and a catalyst unit. The plasma unit generates energetic plasma species which react with particulate matters and nitrogen oxides contained in the exhaust gas. The catalyst unit has a catalyst which reacts with the exhaust gas. The plasma unit is disposed upstream relative to the catalyst unit in a direction of flow of the exhaust gas and the system provides sequential purification for the particulate matters and the nitrogen oxides.

System and method for purifying an exhaust gas

A purification catalyst for exhaust gas has high purification performance for the exhaust gas even under a high oxygen concentration atmosphere. The purification catalyst for exhaust gas contains cerium oxide, zeolite carrying Pt, and tin or a tin oxide.

Purification catalyst for exhaust gas

An exhaust gas purifying catalyst has an Ir powder. The Ir powder has a two peak particle size distribution, with a peak in a particle size D>25 nm region, and the other peak in a particle size D<25 nm region, respectively.

Exhaust gas purifying catalyst

An active solid polymer electrolyte membrane in a solid polymer type fuel cell comprises a solid polymer electrolyte membrane and a plurality of precious metal catalyst particles supported on the surfaces of the aforementioned solid polymer electrolyte membrane by ion exchange and distributed uniformly over the surfaces thereof. In accordance with the use of this active solid polymer electrolyte membrane the ability to generate power can be enhanced.

Active solid polymer electrolyte membrane in solid polymer type fuel cell and process for the production thereof

A catalyst for purifying exhaust gas is disclosed which can attain a high percentage of NO purification in an oxygen-excess atmosphere even after exposure to a hydrothermal environment. The catalyst for purifying exhaust gas comprises a combination of a carrier having platinum deposited thereon and CeO having an average crystallite diameter D satisfying D&gE;13.0 nm. The carrier is made of a gallosilicate having an SiO /Ga O molar ratio M satisfying 100&lE;M&lE;1,230.

Catalyst for purification of exhaust gas

A composite catalyst includes a first catalyst part containing an Ir catalyst and a second catalyst part covering the first catalyst part and containing a perovskite type composite oxide. The perovskite type composite oxide contributes mainly to oxidation reaction such as NO&plus;O,&rarr;NO,in an atmosphere of excess oxygen while the Ir catalyst contributes mainly to reduction reaction with HC (hydrocarbon) as a reducing agent such as NO,&plus;HC&plus;O,&rarr;N,&plus;CO,&plus;H,O.

Composite catalyst for purification of exhaust gas

An exhaust emission control catalyst having an excellent NOx converting capability includes a modified alumina which has a .theta.-phase and an .alpha.-phase and has an .alpha.-conversion rate R in a range of 0.5 %.ltoreq.R.ltoreq.95 %, and a catalytic metal carried in the modified alumina, e.g., platinum (Pt). In addition, a catalyst including a catalyst material which is the above-described catalyst including the modified alumina and the catalytic metal, and an aluminosilicate or cerium oxide (CeO.sub.2), also has an excellent NOx converting capability.

Exhaust emission control catalyst and process for producing the same

An adsorbent exhibiting an excellent adsorption ability to nitrogen oxides (NO) is made from an oxide-based ceramics having an average crystallite grain size D in a range of D&lt;500 .ANG., e.g., CeO.sub.2. A catalyst is formed from, for example, an cerium oxide (CeO.sub.2) and a zeolite. A content C of CeO.sub.2 in the catalyst is set in a range of 10% by weight .ltoreq.CA.ltoreq.80% by weight. The zeolite adsorbs hydrocarbon (HC). The hydrocarbon (HC) adsorbed is oxidized into active CHO which acts to reduce the nitrogen oxides (NO) adsorbed by the CeO.sub.2.

Adsorbent for nitrogen oxides and exhaust emission control catalyst

In an exhaust emission control system in an internal combustion engine which includes a spark plug disposed to face a combustion chamber, an intake system having a fuel injection valve disposed therein, an exhaust system having a catalytic converter incorporated therein and filled with a catalyst for reducing nitrogen oxide (NO.sub.x) in the presence of hydrocarbons in an oxidizing atmosphere, and an exhaust gas circulation amount control means capable of measuring and controlling the amount of exhaust gas circulated from the exhaust system to the intake system. The amount of exhaust gas circulated by the exhaust gas circulation amount control means the amount and timing of fuel injected by the fuel injection valve and the timing of ignition of the spark plug are controlled by a control unit, so that the amount of NO.sub.x discharged, is detected by the NO.sub.x detector in the exhaust system at a location downstream from the catalytic converter, is equal to or less than an acceptable amount of NO.sub.x discharged which acceptable amount is set in accordance with the number of revolutions of the engine detected by a revolution-number detector as well as the engine load detected by a load detector. Thus, it is possible to control the concentration and type of hydrocarbons and the temperature of the catalyst to increase the elimination rate of NO.sub.x.

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Wako, Japan

Kazuhide Terada