In an exhaust gas purification catalyst, a catalytic component (100) containing a first oxide (21), a second oxide (22), and a precious metal (30) is supported on a three-dimensional structure (10); the ratio of the amount of precious metal (30) supported on the first oxide (21) to the total amount of precious metal (30) supported on the first oxide (21) and precious metal (30) supported on the second oxide (22), or the ratio of the amount of precious metal (30) supported on the second oxide (22) to the total amount of precious metal (30) supported on the first oxide (21) and precious metal (30) supported on the second oxide (22) is 70% or more to 100% or less, as measured by an electron probe microanalyzer (EPMA); and the amount of carbon monoxide that the precious metal (30) can adsorb per unit mass is 15 mL/g or more to 100 mL/g or less.

Disclosed herein are compositions comprising zirconium and cerium having a surprisingly small particle sizes. The compositions disclosed herein contain zirconium, cerium, optionally yttrium, and optionally one or more rare earths other than cerium and yttrium The compositions exhibit a particle size characterized by a Dso value of about 20 μm to about 45 μm and a D.sub.99 value of about 55 μm to about 1 00 μm. Further disclosed are processes of producing these compositions using oxalic acid in the process. The compositions can be used as a catalyst and/or part of a catalytic system for automobile exhaust gas.

In accordance with the technology herein disclosed, an exhaust gas purification catalyst exhibiting a high exhaust gas purifying performance using a new rare earth-containing material is provided. The exhaust gas purification catalyst herein disclosed includes a base material and a catalyst layer formed on the surface of the base material. The catalyst layer of such an exhaust gas purification catalyst includes rare earth-carrying alumina 50 including a primary particle of a rare earth particle 40 including at least one rare earth element carried on the surface of an alumina carrier 30 including alumina, and the average particle diameter D.sub.50 based on TEM observation of the rare earth particle 40 in the rare earth-carrying alumina 50 is 10 nm or less. As a result of this, it is possible to provide an exhaust gas purification catalyst having high NOx adsorption performance and CO adsorption performance

In accordance with the technology herein disclosed, an exhaust gas purification catalyst exhibiting a high exhaust gas purifying performance using a new rare earth-containing material is provided. The exhaust gas purification catalyst herein disclosed includes a base material and a catalyst layer formed on the surface of the base material. The catalyst layer of such an exhaust gas purification catalyst includes rare earth-carrying alumina 50 including a primary particle of a rare earth particle 40 including at least one rare earth element carried on the surface of an alumina carrier 30 including alumina, and the average particle diameter D.sub.50 based on TEM observation of the rare earth particle 40 in the rare earth-carrying alumina 50 is 10 nm or less. As a result of this, it is possible to provide an exhaust gas purification catalyst having high NOx adsorption performance and CO adsorption performance

Described is a catalyst for preparing hydrogen peroxide by an anthraquinone process and for regenerating a working solution and a method of preparing the catalyst. The catalyst contains palladium, magnesium, and cerium components uniformly distributed in alumina. Alternatively, the catalyst contains a palladium component distributed in a ring shape in an alumina sphere and magnesium and cerium components uniformly distributed in the alumina.

Described is a catalyst for preparing hydrogen peroxide by an anthraquinone process and for regenerating a working solution and a method of preparing the catalyst. The catalyst contains palladium, magnesium, and cerium components uniformly distributed in alumina. Alternatively, the catalyst contains a palladium component distributed in a ring shape in an alumina sphere and magnesium and cerium components uniformly distributed in the alumina.

A catalyst for catalytic oxidation-deoxidation method of unsaturated hydrocarbon-containing gas has a carrier, an active component, a first co-agent component, and a second co-agent component loaded on the carrier respectively. The active component is one or more selected from the group consisting of oxides of Pt, Pd, Ru, Rh, Ag and Ir. The first co-agent component has one or more selected from the group consisting of a rare earth metal element, a group IVB metal element and a group VIII metal element; and the second co-agent component has one or more alkali metal element and alkaline earth metal element. The deoxidation method using the catalyst eliminates the need to add a reducing gas such as H.sub.2, allows hydrocarbons to react directly with oxygen to produce CO.sub.2 and H.sub.2O, achieves the goal of deoxidating a hydrocarbon-containing tail gas, and can prevent the generation of carbon deposits.

A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprising: a substrate comprising an inlet end and an outlet end with an axial length L; and a first catalytic region on the substrate; wherein the first catalytic region comprises a first PGM component and a first alumina, wherein the first alumina is doped with a first dopant of at least 5 wt. %, and wherein the first dopant is selected from the group consisting of Zr, Ta, Mo, W, Ti, Nb, and a combination thereof.

A zirconia-based porous body including an oxide of a rare earth element, in which when a pore volume in a pore distribution range of 30 nm or more and 200 nm or less after heating at 1150° C. for 12 hours under atmospheric pressure is defined as pore volume A and a pore volume in a pore distribution range of 30 nm or more and 200 nm or less before heating is defined as pore volume B, the pore volume A is 0.10 ml/g or more and 0.40 ml/g or less, and a pore volume retention ratio X in a pore distribution range of 30 nm or more and 200 nm or less represented by a formula [[(pore volume A)/(pore volume B)]×100] is 25% or more and 95% or less.

An embodiment ceria-alumina support (CeO.sub.2—Al.sub.2O.sub.3 support) includes a nano-ceria having a shape of a polygonal bipyramid or a truncated polygonal bipyramid supported on alumina. An embodiment noble metal catalyst for treating exhaust gas includes a noble metal deposited on a ceria-alumina support (CeO.sub.2—Al.sub.2O.sub.3 support) that includes a nano-ceria having a shape of a polygonal bipyramid or a truncated polygonal bipyramid supported on alumina. An embodiment method for affecting resistance to sulfur-poisoning of a noble metal catalyst through structural transformation of nano-ceria supported on alumina includes performing a hydrothermal treatment of ceria supported on γ-alumina.