In order to provide an exhaust gas purification catalyst capable of purifying hydrocarbons, carbon monoxide, and nitrogen oxides in exhaust gas at low temperatures, the exhaust gas purification catalyst according to the present invention includes: a region (2) containing palladium on a three-dimensional structure (1), and a first region (3) and a second region (4) provided on the region (2) in order from an inflow side of exhaust gas to an outflow side of exhaust gas. The concentration of neodymium contained in the first region (3) is higher than the concentration of neodymium contained in the second region (4).

A method for preparing a sol comprising TiO.sub.2 and ZrO.sub.2 and/or hydrated forms of TiO.sub.2 and ZrO.sub.2. The method includes mixing a material which includes metatitanic acid in an aqueous phase with a zirconyl compound or with a mixture of several zirconyl compounds. The material is provided either as a suspension or as a filter cake from the sulfate method. The material includes a H.sub.2SO.sub.4 content of 3 to 15 wt.-% relative to a quantity of TiO.sub.2 in the material. The zirconyl compound or the mixture of several zirconyl compounds is mixed in a quantity that is sufficient to provide the sol depending on the H.sub.2SO.sub.4 content.

A NO.sub.x absorber catalyst for treating an exhaust gas from a lean burn engine. The NO.sub.x absorber catalyst comprises a molecular sieve catalyst comprising a noble metal and a molecular sieve, wherein the molecular sieve contains the noble metal; an oxygen storage material for protecting the molecular sieve catalyst; and a substrate having an inlet end and an outlet end.

The invention provides a process for preparing a methane oxidation catalyst comprising a mechanochemical treatment, a methane oxidation catalyst thus prepared and a method of oxidizing methane.

The invention provides a catalyst article including a substrate underlying a multi-layer catalyst composition and a multi-layer catalyst composition comprising a first layer and a second layer, the first layer positioned between the substrate and the second layer, wherein the first layer comprises a first porous refractory oxide material impregnated with at least one base metal component and the second layer comprises a second porous refractory oxide material impregnated with at least one platinum group metal. Either the second porous refractory oxide material is a porous refractory oxide material other than alumina or the catalyst composition further comprises an intermediate layer between the first layer and the second layer, the intermediate layer comprising a refractory oxide material other than alumina. Methods of making and using the catalyst article are also provided, as well as emission treatment systems comprising the catalyst article.

Disclosed in certain embodiments is a sulfur tolerant catalytic system that includes a catalytic material coated onto a substrate.

A NO.sub.x adsorber catalyst composition, a NO.sub.x adsorber catalyst and its use in an emission treatment system for internal combustion engines, is disclosed. The NO.sub.x adsorber catalyst composition a support material and one or more platinum group metals disposed on the support material, wherein the support material comprises a NO.sub.x storage enhancer.

The invention relates to a process of manufacture of a solid catalyst made of a support coated with a thin catalytic layer and to a process for eliminating gaseous and/or particulate pollutants in an exhaust gaz. The process of the invention of manufacture of a solid catalyst (1) comprising a support (2) coated with a catalytic layer (3) comprises the following steps: a) preparing a solution A by dissolving alkoxide and/or chloride precursors of at least one metal selected in the group consisting of Al, Si, Ti, Zr, Fe, Zn, Nb, V and Ce in a solvent S1 having a partition coefficient lower than 1 and containing less than 5% by volume of water, b) preparing a solution B containing a surfactant, an organic acid and/or hydrochloride acid (HCl) in a solvent S2 having a partition coefficient lower than 5, preferably less than 2, even more preferably less than 1, c) mixing solution A and solution B together, thereby obtaining a washcoat solution C, d) dip-coating the support (2) having OH groups at its surface into washcoat solution C, e) drying the coated support (2) obtained in step d), f) calcinating the dried coated support (2) obtained in step e). The process of the invention finds application in the field of elimination of VOC's, CO and/or particulate pollutants in an exhaust gaz.

Catalytic articles comprising a substrate having a catalytic coating thereon, the catalytic coating comprising a catalytic layer; where the catalytic layer comprises a noble metal component on support particles and where the support particles have a bimodal particle size distribution comprising micron-scaled particles and nano-scaled particles are highly effective for treating exhaust streams of internal combustion engines. The articles are prepared via a method comprising providing a first mixture comprising micron-scaled support particles; providing a second mixture comprising nano-scaled support particles and a noble metal component having an initial pH; admixing the first and second mixtures; applying the admixture to a substrate to form a catalytic layer and calcining the substrate.

The present disclosure provides catalytic materials and catalytic articles formed therewith. The catalytic materials particularly can include an oxygen storage component comprising a solid solution of at least one platinum group metal and at least one rare earth metal oxide. In one or more embodiments, catalytic materials can include a solid solution of a platinum group metal (e.g., palladium) and a mixed metal oxide (e.g., ceria/zirconia).