An exhaust gas purifying composition of the present invention contains zeolite that is BEA zeolite having an SiO.sub.2/Al.sub.2O.sub.3 molar ratio of greater than 25 and 600 or less and containing phosphorus. Furthermore, the exhaust gas purifying composition preferably contains zirconium in addition to phosphorus. Furthermore, the zeolite has an SiO.sub.2/Al.sub.2O.sub.3 molar ratio of from 30 to 150. The present invention provides an exhaust gas purifying composition having excellent HC adsorbability for exhaust gas purification in internal combustion engines such as gasoline engines.

An exhaust system for an internal combustion engine, the exhaust system comprising, a lean NO.sub.x trap, a NO.sub.x storage and reduction zone on a wall flow monolithic substrate having a pre-coated porosity of 50% or greater, the NO.sub.x storage and reduction zone comprising a platinum group metal loaded on one or more first support, the or each first support comprising one or more alkaline earth metal compound, and a selective catalytic reduction zone on a monolithic substrate, the selective catalytic reduction zone comprising copper or iron loaded on a second support, the second support comprising a molecular sieve.

The present invention relates to a ferritic stainless steel according to the present invention, containing, in mass %: 0.001%C0.020%, 0.05%Si0.50%, 0.1%Mn1.0%, 15.0%Cr25.0%, Mo<0.50%, 0.50%W5.00%, and 0.01%Nb0.50%, with a balance being Fe and unavoidable impurities, having a content (coarse Laves phase ratio) of coarse Laves phase having a diameter of 0.50 m or more being 0.1% or less, and having an average grain size being 30 m or more and 200 m or less.

Method for the preparation of a catalysed monolithic body or a catalysed particulate filter by capillary suction of sol-solution containing catalytically active material and metal oxide catalyst carriers or precursors thereof into pores of monolithic substrate.

Disclosed herein are emission treatment systems, articles, and methods for selectively reducing NOx compounds. The systems include a hydrogen generator, a hydrogen selective catalytic reduction (H.sub.2-SCR) article, and one or more of a diesel oxidation catalyst (DOC) and/or a lean NOx trap (LNT) and/or a low temperature NOx adsorber (LTNA). Certain articles may comprise a zone coated substrate and/or a layered coated substrate and/or an intermingled coated substrate of one or more of the H.sub.2-SCR and/or DOC and/or LNT and/or LTNA catalytic compositions.

An exhaust gas after-treatment unit for an internal combustion engine, particularly for a motor vehicle, includes a first selective catalytic reduction (SCR) catalytic converter through which the exhaust gas from the internal combustion engine can flow and at least one particle filter for retaining the soot particles from the exhaust gas, The particle filter, which is located downstream from the first SCR catalytic converter, is equipped with a heavy metal and precious metal free catalyzing coating which oxidizes the soot particles retained by the particle filter, where downstream from the particle filter there is a second SCR catalytic converter through which the exhaust gas can flow.

Active catalysts for the treatment of a low temperature exhaust gas stream are provided containing palladium oxides dispersed on a spinel oxide for the direct, lean removal of nitrogen oxides from the exhaust gas stream. The low temperature (from about 400 C. to about 650 C.), direct decomposition is accomplished without the need of a reductant molecule. In one example, PdO may be dispersed on a surface of a metal oxide support, such as Co.sub.3O.sub.4 spinel oxide, synthesized using wet impregnation techniques. The PdO/Co.sub.3O.sub.4 catalyst system converts nitric oxide to nitrogen gas with high product specificity, avoiding the production of a significant concentration of the undesirable N.sub.2O product.

Active catalysts for the treatment of a low temperature exhaust gas stream are provided containing palladium oxides dispersed on a spinel oxide for the direct, lean removal of nitrogen oxides from the exhaust gas stream. The low temperature (from about 400 C. to about 650 C.), direct decomposition is accomplished without the need of a reductant molecule. In one example, PdO may be dispersed on a surface of a metal oxide support, such as Co.sub.3O.sub.4 spinel oxide, synthesized using wet impregnation techniques. The PdO/Co.sub.3O.sub.4 catalyst system converts nitric oxide to nitrogen gas with high product specificity, avoiding the production of a significant concentration of the undesirable N.sub.2O product.

A lean NO.sub.x trap catalyst and its use in an emission treatment system for internal combustion engines is disclosed. The lean NO.sub.x trap catalyst comprises a first layer, a second layer, and a third layer.

A catalyst 20 provided for a filter body for combusting PM contains activated aluminas 21 and 22, active-oxygen-release materials 23 and 24, catalytic metal 25, and alkali earth metal 26. The alkali earth metal 26 is loaded on each of the activated aluminas 21 and 22, and the active-oxygen-release materials 23 and 24. A percentage by mass of the alkali earth metal 26, loaded on the active-oxygen-release materials 23 and 24, to the active-oxygen-release material is smaller than a percentage by mass of the alkali earth metal 26, loaded on the activated aluminas 21 and 22, to the activated alumina.