An exhaust gas purification catalyst includes: a first catalyst unit that consists of a hydrogen generating catalyst including a noble metal and an oxide that contains lanthanum, zirconium and an additional element such as neodymium; a second catalyst unit that consists of an oxygen storage/release material and a perovskite oxide disposed in contact with the oxygen storage/release material and represented by the general formula La.sub.xM1.sub.1-xM2O.sub.3-δ, where La is lanthanum, M1 is at least one element selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca), M2 is at least one element selected from the group consisting of iron (Fe), cobalt (Co) and manganese (Mn), x satisfies 0<x≦1, and δ satisfies 0≦δ≦1; and a holding material that holds the first catalyst unit and the second catalyst unit in a mutually separated state.

Catalysts and catalytic methods are provided. The catalysts and methods are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane.

Described is a selective catalytic reduction material comprising a spherical particle including an agglomeration of crystals of a molecular sieve. The catalyst is a crystalline material that is effective to catalyze the selective catalytic reduction of nitrogen oxides in the presence of a reductant at temperatures between 200° C. and 600° C. A method for selectively reducing nitrogen oxides and an exhaust gas treatment system are also described.

The present disclosure relates to the technical field of industrial waste gas purification, in particular to a core-shell structured catalyst, a preparation method and use thereof. The present disclosure provides a core-shell structured catalyst including a metal oxide-molecular sieve as a core and porous silica (SiO.sub.2) as a shell, where the metal oxide-molecular sieve includes a molecular sieve and a metal oxide loaded on the molecular sieve, the metal oxide includes an oxide of a first metal and an oxide of a second metal, the first metal is Fe, Cu, Ti, Ni or Mn, and the second metal is Ce or La. The core-shell structured catalyst of the present disclosure can enable effective removal of HCN and AsH.sub.3 at the same time with a stable effect, and no secondary pollution.

Disclosed are a composite oxide which is capable of maintaining a large volume of pores even used in a high temperature environment, and which has excellent heat resistance and catalytic activity, as well as a method for producing the composite oxide and a catalyst for exhaust gas purification employing the composite oxide. The composite oxide contains cerium and at least one element selected from aluminum, silicon, or rare earth metals other than cerium and including yttrium, at a mass ratio of 85:15 to 99:1 in terms oxides, and has a property of exhibiting a not less than 0.30 cm.sup.3/g, preferably not less than 0.40 cm.sup.3/g volume of pores with a diameter of not larger than 200 nm, after calcination at 900° C. for 5 hours, and is suitable for a co-catalyst in a catalyst for vehicle exhaust gas purification.

This exhaust gas purifying catalyst is provided with a substrate and a catalyst layer formed on a surface of the substrate. The catalyst layer contains zeolite particles that support a metal, and a rare earth element-containing compound that contains a rare earth element. The rare earth element-containing compound is added in such an amount that the molar ratio of the rare earth element relative to Si contained in the zeolite is 0.001 to 0.014 in terms of oxides.

Catalytic articles having a high porosity substrate containing platinum, palladium or a mixture thereof, in walls of the high porosity substrate and an SCR catalyst coating on a wall of the high porosity substrate are disclosed. The platinum, palladium or mixture thereof can be present in the wall of the high porosity support as a metal, or as a supported platinum, palladium or a mixture thereof. The catalytic articles are useful for selective catalytic reduction (SCR) of NOx in exhaust gases and in reducing the amount of ammonia slip. Methods for producing such articles are described. Methods of using the catalytic articles in an SCR process, where the amount of ammonia slip is reduced, are also described.

[Problem] Provided is an exhaust gas purification catalyst capable of exhibiting even higher exhaust gas purification performance without impairing Pd catalytic activity, and an exhaust gas purification system using the exhaust gas purification catalyst.

[Solution] Provided is an exhaust gas purification catalyst comprising a substrate and a catalyst layer provided on the substrate, said catalyst having a first section located upstream along a flow direction of the exhaust gas and a second section located downstream from the first section; the catalyst layer in the first section comprises a first catalyst layer comprising palladium and a second catalyst layer comprising rhodium and covering the first catalyst layer, wherein a pore volume proportion is 12% or more and less than 18% wherein the pore volume proportion is a proportion of a total volume of the pores, which have a pore diameter of 0.06 μm to 30.0 μm as measured by mercury press-in method and existing in the substrate and the catalyst layer in the first section to a volume of a entire first section; and a wash coat amount is 100 g/L to 190 g/L, wherein a wash coat amount is a mass per unit volume of the catalyst layer in the first section to the volume of the substrate existing in the first section.

The present invention provides catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article catalyst article comprises: a substrate which is a wall-flow filter having an inlet end and an outlet end and an axial length L therebetween, a plurality of inlet channels extending from the inlet end and a plurality of outlet channels extending from the outlet end, wherein the plurality of inlet channels comprise a first catalyst composition extending from the inlet or outlet end for at least 50% of L and the plurality of outlet channels comprise a second catalyst composition extending from the outlet or inlet end for at least 50% of L, wherein the first and second catalyst compositions overlap by at most 80% of L, and wherein the first and second catalyst compositions each independently comprise a particulate oxygen storage component (OSC) having a first D90 and a particulate inorganic oxide having a second D90 and: i) the first D90 is less than 1 micron and the second D90 is from 1 to 20 microns; or ii) the second D90 is less than 1 micron and the first D90 is from 1 to 20 microns.

The present disclosure relates to ruthenium promoter catalyst compositions. The ruthenium promoter catalyst compositions comprise ruthenium metal species, an oxide support material, and a promoter species independently selected from the group consisting of La, Rb, Y, Yb, K, Cs, and Ba, or hydroxides, nitrates or oxides thereof. The present disclosure also relates to various methods, processes, systems, membranes and/or reactors, which can utilise the ruthenium promoter catalyst compositions, for example in ammonia synthesis.