An oxygen storage material including a ceria-zirconia based composite oxide containing a composite oxide of ceria and zirconia, wherein the ceria-zirconia based composite oxide comprises at least one rare-earth element selected from the group consisting of lanthanum, yttrium, and neodymium, and an amount of the rare-earth element(s) contained in total is 1 to 10% by atom in terms of element relative to a total amount of cerium and zirconium in the ceria-zirconia based composite oxide, 60 to 85% by atom of the entire amount of the rare-earth element(s) is contained in a near-surface upper-layer region extending from a surface of each primary particle of the ceria-zirconia based composite oxide to a depth of 50 nm in the primary particle, and 15 to 40% by atom of the entire amount of the rare-earth element(s) is contained in a near-surface lower-layer region extending from a depth of 50 nm to a depth of 100 nm in the primary particle, a content ratio of cerium and zirconium in the ceria-zirconia based composite oxide is in a range of 40:60 to 60:40 in terms of an atomic ratio ([Ce]:[Zr]), and the ceria-zirconia based composite oxide has an intensity ratio {I(14/29) value} between a diffraction line at 2θ=14.5° and a diffraction line at 2θ=29° which satisfies the following condition:
I(14/29) value≥0.032,
where the intensity ratio {I(14/29) value} is determined from an X-ray diffraction pattern using CuKα obtained by an X-ray diffraction measurement conducted after heating in air under a temperature condition of 1100° C. for 5 hours.

The present disclosure generally relates to emission control catalyst articles comprising a platinum group metal (PGM) enriched zone, methods of making such emission control catalyst articles, and methods of using such emission control catalyst articles.

The present disclosure generally relates to emission control catalyst articles comprising a platinum group metal (PGM) enriched zone, methods of making such emission control catalyst articles, and methods of using such emission control catalyst articles.

An object of the present invention is to provide an exhaust gas purification catalyst composition and an exhaust gas purification catalyst, each of which includes a pyrochlore-type CeO.sub.2—ZrO.sub.2-based complex oxide having an improved oxygen storage capacity (particularly, an improved oxygen storage capacity after being exposed to a high temperature environment), and, in order to achieve the above-mentioned object, the present invention provides an exhaust gas purification catalyst composition and an exhaust gas purification catalyst, each of which contains a pyrochlore-type CeO.sub.2—ZrO.sub.2-based complex oxide that contains Y and Mg and thus exhibits an excellent oxygen storage capacity (particularly, an excellent oxygen storage capacity after being exposed to a high temperature environment).

An object of the present invention is to provide an exhaust gas purification catalyst composition and an exhaust gas purification catalyst, each of which includes a pyrochlore-type CeO.sub.2—ZrO.sub.2-based complex oxide having an improved oxygen storage capacity (particularly, an improved oxygen storage capacity after being exposed to a high temperature environment), and, in order to achieve the above-mentioned object, the present invention provides an exhaust gas purification catalyst composition and an exhaust gas purification catalyst, each of which contains a pyrochlore-type CeO.sub.2—ZrO.sub.2-based complex oxide that contains Y and Mg and thus exhibits an excellent oxygen storage capacity (particularly, an excellent oxygen storage capacity after being exposed to a high temperature environment).

A cerium-zirconium-aluminum-based composite material, a cGPF catalyst and a preparation method thereof are provided. The cerium-zirconium-aluminum-based composite material adopts a stepwise precipitation method, firstly preparing an aluminum-based pre-treated material, then coprecipitating the aluminum-based pre-treated material with zirconium and cerium sol, and finally roasting at high temperature to obtain the cerium-zirconium-aluminum-based composite material. The cerium-zirconium-aluminum-based composite material has better compactness and higher density, and when it is used in cGPF catalyst, it occupies a smaller volume of pores on the catalyst carrier, such that cGPF catalyst has lower back pressure and better ash accumulation resistance, which is beneficial to large-scale application of cGPF catalyst.

A cerium-zirconium-aluminum-based composite material, a cGPF catalyst and a preparation method thereof are provided. The cerium-zirconium-aluminum-based composite material adopts a stepwise precipitation method, firstly preparing an aluminum-based pre-treated material, then coprecipitating the aluminum-based pre-treated material with zirconium and cerium sol, and finally roasting at high temperature to obtain the cerium-zirconium-aluminum-based composite material. The cerium-zirconium-aluminum-based composite material has better compactness and higher density, and when it is used in cGPF catalyst, it occupies a smaller volume of pores on the catalyst carrier, such that cGPF catalyst has lower back pressure and better ash accumulation resistance, which is beneficial to large-scale application of cGPF catalyst.

The present invention relates to a mixed oxide of aluminium, of zirconium, of cerium, of lanthanum and optionally of at least one rare-earth metal other than cerium and lanthanum that makes it possible to prepare a catalyst that retains, after severe ageing, a good thermal stability and a good catalytic activity. The invention also relates to the process for preparing this mixed oxide and also to a process for treating exhaust gases from internal combustion engines using a catalyst prepared from this mixed oxide.

The present invention relates to a mixed oxide of aluminium, of zirconium, of cerium, of lanthanum and optionally of at least one rare-earth metal other than cerium and lanthanum that makes it possible to prepare a catalyst that retains, after severe ageing, a good thermal stability and a good catalytic activity. The invention also relates to the process for preparing this mixed oxide and also to a process for treating exhaust gases from internal combustion engines using a catalyst prepared from this mixed oxide.

The invention relates to a composition containing a catalyst having high catalytic stability for conducting oxidative coupling of methane (OCM) at high carbon efficiency, while improving both methane and oxygen conversion. Particularly, the inventive catalyst is a metal oxide supported catalyst, which contains an alkali metal promoter and a mixed metal oxide component having at least one alkali earth metal and at least one rare earth metal. The metal oxide support is selected in a manner, such that at least a portion of the metal oxide support is capable of reacting with at least a part or whole of the alkali metal promoter under conditions of calcination during catalyst preparation. The invention further provides a method for preparing such a metal oxide supported catalyst composition, using a calcination process. Additionally, the invention further describes a process for producing C.sub.2+ hydrocarbons, using such a catalyst composition.