An exhaust system for a compression ignition engine comprising an oxidation catalyst for treating carbon monoxide (CO) and hydrocarbons (HCs) in exhaust gas from the compression ignition engine, wherein the oxidation catalyst comprises: a platinum group metal (PGM) component selected from the group consisting of a platinum (Pt) component, a palladium (Pd) component and a combination thereof; an alkaline earth metal component; a support material comprising a modified alumina incorporating a heteroatom component; and a substrate, wherein the platinum group metal (PGM) component, the alkaline earth metal component and the support material are disposed on the substrate.

An exhaust gas-purifying catalyst includes a support and a catalytic metal supported thereby. The support includes a composite oxide represented by AO.xB.sub.2-C.sub.O.sub.3, wherein A represents at least one of an element having a valence of 1 and an element having a valence of 2, B represents an element having a valence of 3, C represents one or more elements selected from iridium, ruthenium, tantalum, niobium, molybdenum, and tungsten, x represents a numerical value of 1 to 6, and represents a numerical value greater than 0 and less than 2. The catalytic metal includes one or more precious metals selected from rhodium, palladium, and platinum.

The invention provides an automotive catalyst composite that includes a catalytic material on a carrier, the catalytic material including a plurality of core-shell support particles including a core and a shell surrounding the core, wherein the core includes a plurality of particles having a primary particle size distribution d.sub.90 of up to about 5 ?m, wherein the core particles include particles of one or more molecular sieves and optionally particles of one or more refractory metal oxides; and wherein the shell comprises nanoparticles of one or more refractory metal oxides, wherein the nanoparticles have a primary particle size distribution d.sub.90 in the range of about 5 nm to about 1000 nm (1 ?m); and optionally, one or more platinum group metals (PGMs) on the core-shell support. The invention also provides an exhaust gas treatment system and related method of treating exhaust gas utilizing the catalyst composite.

A honeycomb structure is formed of a porous ceramic material and has pores in the structural body, wherein cerium dioxide is present in a state that it is incorporated in the structural body in the ceramic material, and at least a part of cerium dioxide particles is exposed on pore surfaces of the pores. The ceramic material includes cordierite or silicon carbide as a major component, the ratio of the cerium dioxide to the ceramic material is in the range of from 1.0% by mass to 10.0% by mass, and at least a part of catalyst particulates of a platinum group element such as platinum or palladium is loaded by the cerium dioxide particles.

An exhaust gas purification catalyst contains an oxide 1 and an oxide 2. The catalyst has pores P.sub.1-260 with a pore size of from 1 nm to 260 nm, that can be measured by the nitrogen absorption method, and the total sum PV.sub.1-260 of the pore volume PV.sub.1-260 of the pores is equal to or greater than 0.79 cm.sup.3/g. The oxide 1 is an oxide with an oxygen release capability. The oxide 2 is represented by La.sub.xM.sub.1-xMO.sub.3- (2), where M is at least one element selected from the group consisting of Ba, Sr and Ca, M is at least one element selected from the group consisting of Fe, Co, Ni and Mn, is the amount of oxygen deficiency, x satisfies 0x1, and satisfies 01.

Provided is catalyst material useful for the selective catalytic reduction of NOx in lean burn exhaust gas, wherein the catalyst material is a hydrothermally stable, low SAR aluminosilicate zeolite loaded with a synergistic combination of one or more transition metals, such as copper, and one or more alkali or alkaline earth metals, such as calcium or potassium.

Composites of mixed metal oxides for an exhaust gas purifying catalyst comprise the following co-precipitated materials by weight of the composite: zirconia in an amount in the range of 55-99%; titania in an amount in the range of 1-25%; a promoter and/or a stabilizer in an amount in the range of 0-20%. These composites are effective as supports for platinum group metals (PGMs), in particular rhodium.

An exhaust gas purification catalyst, characterized by having a catalyst layer containing palladium, rhodium, and alumina, which supports a sulfate of an alkaline-earth metal selected from barium sulfate and strontium sulfate, and the correlation coefficients .sub.Pd,AE and .sub.Rh,AE calculated from the characteristic X-ray intensity measured using an electron beam micro-analyzer for the palladium, rhodium, and alkaline-earth metal being +0.75 to +1.00 and 0.00 to +0.25, respectively, using 350 points as measurement points obtained by equally dividing the catalyst layer into 351 parts in the thickness direction on a virtual straight line that runs through the catalyst layer in the thickness direction.

Provided is an exhaust gas purification filter including a substrate comprising a plurality of porous partitions, wherein the partitions form an exhaust gas flow path, a porous catalytic layer is provided on the partitions and the catalytic layer having a thickness of 10 m or greater is provided over at least 20% of the total length of the partitions in the lengthwise direction thereof, and the catalytic layer having a thickness of 10 m or greater is not present on the partitions 15 mm from an outflow side.

The present invention is to provide a NOx storage reduction catalyst for purifying exhaust gas capable of efficiently removing carbon monoxide (CO), a hydrocarbon (HC), and a nitrogen oxide (NOx), in particular NOx, which are harmful components contained in exhaust gas. The NOx storage reduction catalyst for purifying exhaust gas of the present invention is characterized by being obtained by using a complex oxide of strontium and cerium as a catalytic active component, in which the complex oxide of strontium and cerium adsorbs 1.0 mL or less of oxygen per gram in a 400 C. atmosphere, and sinters a precursor at 300 C. or more.