Hitachi, Ltd.

Honda Motor Co., Ltd.

Kojiro Okude

Hisao Yamashita

Osamu Kuroda

Yuichi Kitahara

Hidehiro Iizuka

Toshio Ogawa

Toshifumi Hiratsuka

Shigeru Azuhata

Ryouta Doi

Norihiro Shinotsuka

Toshio Manaka

Masato Kaneeda

Hiroshi Hanaoka

Kousei Nagayama

Akira Kato

Masahiro Nishizawa

Yoshifumi Tomita

Yutaka Misawa

Tomoji Oishi

Kenji Tochigi

Sachiko Maekawa

Morio Fujitani

Hiroshi Kodairajousui Hausu 205 Hanaoka

An exhaust gas purification apparatus for use in an internal combustion engine comprises an exhaust gas duct connected to the engine through which the exhaust gas containing NOx gas passes and a catalyst so disposed in the exhaust gas duct that it contacts with the exhaust gas. The catalyst chemically adsorbs NOx under the condition that a stoichiometric amount of a gaseous oxidizing agent present in the exhaust gas is larger than that of a gaseous reducing agent present in the exhaust gas for reducing NOx, while NOx being adsorbed is catalytically reduced in the presence of the reducing agent under the condition that the stoichiometric amount of the oxidizing agent is not larger that of the reducing agent. Thereby, NOx, the lean burn exhaust gas in the engine can be effectively made harmlessly.

Exhaust gas purification apparatus of internal combustion engine and catalyst for purifying exhaust gas of internal combustion engine

In a method and apparatus for removing nitrogen oxides from the exhaust gas of a lean-burn automobile, a CO adsorbent component, which may, for example be made of Pd, Ru or Ir, is contained in an exhaust gas cleaning catalyst which captures NOx when the air-fuel ratio of exhaust gas is higher than theoretical air-fuel ratio, and reduces the captured NOx when the air-fuel ratio of exhaust gad is less than or equal to the theoretical air-fuel ratio. The catalyst, which includes Rh, Pt, and element selected from among the alkaline and alkaline earth metals (Na, Mg, K, Li, Cs, Sr and Ca), and a CO adsorbent material comprising Pd, Ir or Ru, has a CO desorption capacity that reaches at maximum level at a temperature within the range from 200 to 220&#xb0; C. when its temperature is increased in a He gas flow at the rate of 5 to 10&#xb0; C./min, after said catalyst is saturated at 100&#xb0; C. Exhaust gas having an air-fuel ratio higher than theoretical air-fuel and exhaust gas having an air-fuel ratio less than or equal to the theoretical air-fuel ratio are alternately made to flow to the catalyst.

Method for cleaning exhaust gas from an internal combustion engine

Nitrogen oxides contained in an exhaust gas emitted from a lean-burn engine-mounted internal combustion engines are eliminated with a high efficiency. In an exhaust gas purification apparatus and process for eliminating nitrogen oxides contained in a combustion exhaust gas emitted from an internal combustion engine with a reducing gas such as carbon monoxide, hydrocarbons, etc. contained in the exhaust gas in the presence of a catalyst, a catalyst comprising all of Rh, Pt and Pd, at least one member selected from alkali metals and alkaline earth metals, and Mn or its compound, supported on a porous carrier is used.

Internal combustion engine exhaust gas purification apparatus, exhaust gas purification process and exhaust gas purification catalyst

In an exhaust gas purification process for eliminating nitrogen oxides contained in a combustion exhaust gas emitted from an internal combustion engine with a reducing gas such as carbon monoxide, hydrocarbons, etc. contained in the exhaust gas in the presence of a catalyst, a catalyst comprising all of Rh, Pt and Pd, at least one member selected from alkali metals and alkaline earth metals, and Mn or its compound, supported on a porous carrier is used.

Exhaust emission control process for internal combustion engines

An exhaust gas purification apparatus for use in an internal combustion engine comprises an exhaust gas duct connected to the engine through which the exhaust gas containing NOx gas passes and a catalyst so disposed in the exhaust gas duct that it contacts with the exhaust gas. The catalyst chemically adsorbs NOx under the condition that a stoichiometric amount of a gaseous oxidizing agent present in the exhaust gas is larger than that of a gaseous reducing agent present in the exhaust gas for reducing NOx, while NOx being adsorbed is catalytically reduced in the presence of the reducing agent under the condition that the stoichiometric amount of the oxidizing agent is not larger that of the reducing agent. Thereby, NOx the lean burn exhaust gas in the engine can be effectively made harmlessly.

An apparatus and method of highly efficiently purifying nitrogen oxides are provided. An NOx chemisorption reduction catalyst chemically absorbs NOx under a condition that an exhaust gas of an internal combustion engine is an oxidizing atmosphere and deoxidizes adsorbed NOx under a reducing atmosphere. An SOx absorbent absorbs SOx contained in the exhaust gas of the oxidizing atmosphere, and deoxidizes and release SOx absorbed in the reducing atmospheric exhaust gas. The catalyst and absorbent are arranged in the exhaust path to purify the exhaust gas while preventing or suppressing SOx-poisoning of the NOx chemisorption reduction catalyst.

Exhaust gas cleaning apparatus and method for internal combustion engine

Exhaust gas purification apparatus of internal combustion engine and

An anti-reflection film is produced on the panel surface of a cathode-ray tube by: (A) preparing a solution for forming an anti-reflection film, which contains water and a metal alkoxide having the formula,

Method for forming and anti-reflection film of a cathode-ray tube, an

Method for forming an anti-reflection film of a cathode-ray tube, an

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Hitachi, Japan

Kojiro Okude