There is provided an exhaust purification apparatus for an internal combustion engine in which a catalyst capable of adsorbing and oxidizing hydrocarbon is provided in an exhaust pipe, the exhaust purification apparatus including temperature detection means for detecting a temperature of the catalyst, estimation means for accumulating a time during which the temperature of the catalyst detected by the temperature detection means is equal to or less than a predetermined temperature, and estimating an amount of hydrocarbon adsorbed on the catalyst from the accumulated time, and control means for controlling fuel ejection of the internal combustion engine in a first ejection mode in which the temperature of the catalyst is increased to a temperature where hydrocarbons adsorbed on the catalyst are oxidized, in a case in which the amount of hydrocarbons estimated by the estimation means exceeds a predetermined upper limit.

Provided is an ammonia slip catalyst article having supported palladium in a top or upstream layer for oxidation of carbon monoxide and/or hydrocarbons, an SCR catalyst either in the top layer or in a separate lower or downstream layer, and an ammonia oxidation catalyst in a bottom layer. Also provided are methods for treating an exhaust gas using the catalyst article, wherein the treatment involves reducing the concentrations of ammonia and optionally carbon monoxide and/or hydrocarbons in the exhaust gas.

This invention relates to a method of regenerating a deactivated catalyst, which carries precious metal components including platinum and palladium and which is used to purify a gas exhausted from a compressed natural gas lean-burn engine. The method includes creating a reduction atmosphere over the catalyst. The creating the reduction atmosphere over the catalyst includes controlling an air-fuel ratio or directly injecting CNG fuel into the catalyst.

An exhaust gas filter for purifying exhaust gases including particulate matter discharged from an internal combustion engine includes a honeycomb structure whose axial direction matches an exhaust gas flow, a plug portion which selectively plugs upstream end faces of the honeycomb structure which faces the exhaust gas flow, and catalyst carried on the honeycomb structure.

The honeycomb structure has a plurality of partition walls and cells surrounded by the partition walls, and pores formed inside partition walls between adjacent cells communicating with each other. The plurality of the cells have open cells which are penetrated in the axial direction and plugged cells having one upstream end which face the exhaust gas flow plugged by the plug portion. The honeycomb structure has a first region which does not carry the catalyst on the partition walls and a second region which carries the catalyst on the partition walls.

An engine is provided with an exhaust gas treatment device which treats exhaust gas. The exhaust gas treatment device is provided with electric parts which detect a state of the exhaust gas purification device. The engine is provided with a cooling water circulation mechanism which circulates cooling water for the engine. Further, the electric parts are arranged in an outer side of the exhaust gas purification device on an extension in a longitudinal direction of the exhaust gas purification device.

An exhaust gas purification catalyst apparatus, which is superior in oxidation performance of, in particular, nitrogen monoxide, among hydrocarbons, carbon monoxide, nitrogen oxides and particulate components such as soot, included in exhaust gas from a lean burn engine, and combustion performance of light oil. The exhaust gas purification apparatus arranged with an oxidation catalyst (DOC) comprising a noble metal component for oxidizing carbon monoxide, hydrocarbons, in particular, nitrogen monoxide among nitrogen oxides, and for combusting light oil, a catalyzed soot filter (CSF) including a noble metal component for collecting a particulate component such as soot and removing by combustion (oxidation). The oxidation catalyst (DOC) has a catalyst layer where platinum (Pt), palladium (Pd) and barium oxide (BaO) are supported on alumina (Al.sub.2O.sub.3) having a pore size of 12 to 120 nm, and ratio of platinum and palladium is 1:1 to 11:2 in weight equivalent.

Provided are an exhaust gas purifying catalyst structure that inhibits foil elongation and improves structural durability and a production method therefor. The exhaust gas purifying catalyst structure has a metal support configured by using an mantle and a metal foil provided in the mantle and forming an exhaust gas flow path, and a catalyst layer provided on a surface forming the flow path of the metal foil, wherein the catalyst layer contains a noble metal, an OSC material containing cerium and a rare earth element other than cerium (non-Ce rare earth element), and alumina, and a content of the non-Ce rare earth element with respect to 100% by mass of the catalyst layer is 2.52% by mass or more and 4.62% by mass or less in terms of an oxide.

A composite oxidation catalyst for use in an exhaust system for treating an exhaust gas produced by a vehicular compression ignition internal combustion engine is disclosed. The composite oxidation catalyst comprises a honeycomb flow-through substrate monolith and two catalyst washcoat zones arranged axially in series on and along the substrate surface.

A sulfur-resistant, high activity methane oxidation catalyst for use in removing methane from gas streams having a concentration of methane by oxidizing the methane. The methane oxidation catalyst is especially useful in processing gas streams that also have a concentration of a sulfur compound. The sulfur-resistant methane oxidation catalyst includes a unique multi-crystalline zirconia as a support for a platinum component and a ruthenium component. The multi-crystalline zirconia contributes to the excellent properties of the catalyst. The platinum and ruthenium components can be included in the methane oxidation catalyst in a specific weight ratio that also contributes to the enhanced properties of the catalyst. The sulfur-resistant methane oxidation catalyst may also include a chloride component that contributes to enhanced properties of the catalyst.