Abstract: A catalyst for use in purifying exhaust gas from an internal combustion engine. The active components of an exhaust gas purification catalyst for an internal combustion engine tend to be melted or softened and then to move outside the carrier, because the components become in contact with exhaust gas at a high temperature. Hence, anchoring materials are provided between carriers in order to suppress the moving of catalytically active components. Anchoring materials 22 do not form compounds with catalytically active components 24, and are selected from substances that do not melt even in contact with exhaust gas at a high temperature. When the active components contain sodium, potassium, cesium, lithium, strontium, barium, noble metals and the like, the best anchoring material is MgO. The anchoring material functions as a barrier that prevents the moving of active components.

Abstract: An exhaust gas purification apparatus for use in an internal combustion engine comprises an exhaust gas duct connected to the engine through which exhaust gas containing NOx gas passes, and a catalyst disposed in the exhaust gas duct such that it contacts the exhaust gas. The catalyst chemically adsorbs NOx when 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, adsorbed NOx is catalytically reduced in the presence of a reducing agent when the stoichiometric amount of the oxidizing agent is not larger that of the reducing agent.

Abstract: An object of the present invention is to provide a new exhaust gas purification apparatus for an internal combustion engine operated under a condition of an air fuel ratio leaner than a theoretical air fuel ratio, a method for purification of exhaust gas and an exhaust gas purification catalyst, which is suitable for suppressing degradation of the NOx purification catalyst by sulfur components.

Abstract: 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.

Abstract: An apparatus for purifying an exhaust gas of a diesel engine, characterized in that it has an NOx adsorption and reduction type catalyst and a diesel particulate filter for oxidizing and removing particulate matters in the exhaust gas, which are provided in the flow route for the exhaust gas and are arranged in the above described order from the upstream of the flow of the exhaust gas. The above arrangement allows the elevation of the temperature of the catalyst with ease and the precise control of the temperature and atmosphere therein, resulting in the achievement of satisfactory NOx purification performance, and the employment of the NOx adsorption and reduction type catalyst allows the enhancement of the rate of reduction of the NO2 captured, which shortens the time to keep a stoichiometric-rich atmosphere to a time of several seconds to several minutes.

Abstract: An exhaust gas purification apparatus for purifying exhaust gas exhausted from a diesel internal combustion engine and containing therein harmful substances including particulates, NOx, HC and CO, at least, comprises a removal part for trapping and removing particulates in the exhaust gas, a purification part for purifying NOx, HC and CO through contact, and a heat transfer part for transferring heat generated in the removal part to the purification part.

Abstract: An exhaust gas purification filter for a diesel internal combustion engine. In this filter, catalyst layers are not formed at portions to which a sealant of the filter is stuck so that a substrate of the honeycomb structure is exposed, but formed at portions to which a substrate of the honeycomb structure is exposed. If the sealant is stuck to catalyst layer portions, because the catalyst layers are brittle and the surfaces thereof have asperities, the fixing strength of the sealant is reduced, so that the sealing portions becomes prone to falling-off under shocks or the like. By exposing the substrate of the honeycomb structure and sticking the sealant to the exposed portions, it is possible to enhance the fixing strength of the sealant and thereby to prevent the sealing portions from falling off.

Abstract: In an exhaust gas purifying apparatus provided with a lean NOx catalyst supporting a catalyst layer, which contains a NOx trapping component, on a honeycomb substrate formed so as not to cause an alkali attack, the invention prevents trapped NOx from being dissociated and exhausted during the time of a rich spike. A NOx reducing catalyst with the function of reducing NOx by a reductant in a rich or stoichiometric condition, e.g., a three-way catalyst, is disposed downstream of the lean NOx catalyst. In the case of increasing the amount of the NOx trapping component in the lean NOx catalyst to enhance a NOx trapping capability, even if a part of trapped NOx is dissociated during the time of the rich spike, the dissociated NOx can be reduced by the NOx reducing catalyst disposed on the downstream side.

Abstract: An exhaust gas purification apparatus for use in an internal combustion engine comprises an exhaust gas duct connected to the engine through which exhaust gas containing NOx gas passes, and a catalyst disposed in the exhaust gas duct such that it contacts the exhaust gas. The catalyst chemically adsorbs NOx when 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, adsorbed NOx is catalytically reduced in the presence of a reducing agent when the stoichiometric amount of the oxidizing agent is not larger that of the reducing agent.

Abstract: 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° C. when its temperature is increased in a He gas flow at the rate of 5 to 10° C./min, after said catalyst is saturated at 100° C.

Abstract: 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.

Abstract: A moisture removal device for an internal combustion engine use exhaust gas purifying device with a trapped moisture amount estimation means which estimates amount of moisture exhausted from an internal combustion engine and trapped in the catalyst, a judgement means which judges whether the estimated value of the trapped moisture amount exceeds a predetermined amount, and means for controlling removal of the moisture trapped in the catalyst, wherein when the estimated value of moisture trapped in the catalyst exceeds the predetermined value, a control of removing the moisture in the catalyst is performed. Whereby, since the moisture trapped by the catalyst can be removed and a possible elution of the catalyst components can be prevented, reduction of exhaust gas purifying performance of the catalyst can be prevented.

Abstract: A catalyst for use in purifying exhaust gas from an internal combustion engine. The active components of an exhaust gas purification catalyst for an internal combustion engine tend to be melted or softened and then to move outside the carrier, because the components become in contact with exhaust gas at a high temperature. Hence, anchoring materials are provided between carriers in order to suppress the moving of catalytically active components. Anchoring materials 22 do not form compounds with catalytically active components 24, and are selected from substances that do not melt even in contact with exhaust gas at a high temperature. When the active components contain sodium, potassium, cesium, lithium, strontium, barium, noble metals and the like, the best anchoring material is MgO. The anchoring material functions as a barrier that prevents the moving of active components.

Abstract: An exhaust gas purification apparatus for purifying exhaust gas exhausted from a diesel internal combustion engine and containing therein harmful substances including particulates, NOx, HC and CO, at least, comprises a removal part for trapping and removing particulates in the exhaust gas, a purification part for purifying NOx, HC and CO through contact, and a heat transfer part for transferring heat generated in the removal part to the purification part.

Abstract: Nitrogen oxides contained in an exhaust gas emitted from a lean-burn engine-mounted internal combustion engines are eliminated with a high efficiency.

Abstract: 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.

Abstract: A moisture removal device for an internal combustion engine use exhaust gas purifying device with a trapped moisture amount estimation means which estimates amount of moisture exhausted from an internal combustion engine and trapped in the catalyst, a judgement means which judges whether the estimated value of the trapped moisture amount exceeds a predetermined amount, and means for controlling removal of the moisture trapped in the catalyst, wherein when the estimated value of moisture trapped in the catalyst exceeds the predetermined value, a control of removing the moisture in the catalyst is performed. Whereby, since the moisture trapped by the catalyst can be removed and a possible elution of the catalyst components can be prevented, reduction of exhaust gas purifying performance of the catalyst can be prevented.

Abstract: An exhaust gas purifying device which can sufficiently perform HC purification even if a lean NOx catalyst included in a metal substrate is used. The exhaust gas purifying device comprises, in an exhaust passage in an internal combustion engine along a flowing direction of the exhaust gas, a lean NOx catalyst including a catalyst layer which purifies nitrogen oxide contained in the exhaust gas under a hyperoxia atmosphere and a metal honeycomb, the lean NOx catalyst having the catalyst layer supported within the metal honeycomb; and a reaction catalyst for subjecting to an oxidation reaction at least hydrocarbon contained in the exhaust gas.

Abstract: A catalyst being formed of a porous supporter supporting alkali metals, Ti and noble metal, or further supporting at least one of rare earth metal and magnesium, being disposed in a flow passage of the internal combustion engine, and being used to purify NOx contained in the exaust gas. The above catalyst has excellent NOx resistance not only to the exaust gas burnt with the stoichiometric air-to-fuel ratio or rich condition, but to the exhaust gas burnt with the lean condition, and furthermore has a high resistivity to poisoning of SOx slightly contained in the fuel.

Abstract: Exhaust gas from internal combustion engines is treated with catalyst comprising an inorganic oxide supporter which supports at least one of noble metals selected from Rh, Pt, and Pd, alkali rare earth metals, rare earth metals, and magnesium in order to remove NOx effectively with superior durability of the catalyst notwithstanding the internal combustion engine is under a stoichiometric operation condition or a lean burning operation condition.