Abstract: Disclosed is a spinel powder obtained by mixing a magnesia raw-material with an electrically fused alumina, followed by firing of the mixture. The particles of the spinel powder are coated with granular spinel particles. Therefore, there are provided a spinel powder and a simple method for producing the same, which is superior in thermal spraying property and has a unique particle shape. In particular, there is provided a method for producing a spinel powder which contributes to a reduction in the variation of characteristics of sensors, for example, as a thermal spraying powder for forming a protective coating of a gas sensor element.

Abstract: Disclosed is an inorganic material that can exhibit an excellent photocatalytic gas decomposition function while maintaining an abrasion resistance on a level that is usually required of this type of inorganic materials. The inorganic material includes an inorganic material base and a photocatalyst layer that is formed by firing and is provided on the surface of the inorganic material base, the photocatalyst layer containing: photocatalyst particles; zirconia particles having a BET specific surface area of not less than 10 m2/g or crystalline zirconia particles having a mean crystallite diameter of less than 20 nm; and an alkali silicate. The inorganic material including the photocatalyst layer exhibits a high photocatalytic gas decomposition function while maintaining an abrasion resistance on a level that is usually required of this type of inorganic materials.

Abstract: The present invention relates to a nickel oxide-stabilized zirconia composite in which nickel oxide is dispersed uniformly, a process for readily producing the composite oxide, and an anode for a solid oxide fuel cell having excellent output characteristics. More specifically, the present invention provides a nickel oxide-stabilized zirconia composite that is produced by sintering a mixture of nickel hydroxide and/or nickel carbonate and a hydroxide of stabilized zirconium.

Abstract: An exhaust gas purification catalyst, which is suitable as a three way catalyst for efficiently purifying carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) in exhaust gas discharged from a gasoline automobile and exhaust gas purification apparatus using the same and an exhaust gas purification method. <The upper layer> A catalyst composition having an activated metal (A), a heat resistant inorganic oxide (B) and a cerium-zirconium-type composite oxide (C) containing a pyrochlore phase in a crystal structure, wherein the activated metal (A) is rhodium. <The lower layer> A catalyst composition having an activated metal (A), a heat resistant inorganic oxide (B) and a cerium-containing oxide (C?) having a cubic crystal and/or tetragonal crystal structure as a major crystal structure, wherein the activated metal (A) is palladium, or palladium and platinum.

Abstract: The present invention provides a cerium oxide-zirconium oxide based composite oxide that has a large OSC at a low temperature and that has a suitable OSC, and a method for readily producing the composite oxide. Specifically, the present invention provides a cerium oxide-zirconium oxide based composite oxide comprising a mixture of (1) a cerium-zirconium composite oxide from a melting process and (2) cerium dioxide from a wet process, and a method for producing a cerium oxide-zirconium oxide based composite oxide, the method comprising dispersing a cerium-zirconium composite oxide from a melting process in a cerium-containing solution, neutralizing the resulting dispersion; and then performing a heat treatment.

Abstract: A sol of the present invention is a sol comprising zirconium oxalate compound as a dispersoid, wherein a mol ratio of oxalic acid to Zr (oxalic acid/Zr) is from 1.2 to 3 and a particle diameter D50 of the dispersoid is from 10 to 100 nm. This sol is produced by adding oxalic acid to a dispersion liquid of zirconium hydroxide, and the addition of oxalic acid is carried out in twice.

Abstract: A catalyst system to be used in an automobile exhaust gas purification apparatus which exerts excellent purification capability to a nitrogen oxide, even when hydrocarbon concentration varies, by subjecting exhaust gas discharged from an automotive internal engine to contacting with a catalyst, an exhaust gas purification apparatus using the same, and an exhaust gas purification method. A catalyst system etc.

Abstract: This invention relates to a cerium-zirconium-base composite oxide, which is useful, e.g., for the purification of exhaust gas discharged from combustion engines such as internal combustion engines and boilers and can release a high level of oxygen in a low temperature region, a method for producing the same, an oxygen storage/release component using the same, an exhaust gas purification catalyst, and an exhaust gas purification method. The cerium-zirconium-base composite oxide satisfies requirements (1) that the oxygen release initiation temperature is 380° C. or below, (2) that the oxygen release amount is not less than 485 ?mol/g, and further (3) that the oxygen release amount at 400° C. is not less than 15 ?mol/g.

Abstract: The present invention provides a catalyst system for vehicle exhaust gas purification devices which exhibit excellent capacity of removing nitrogen oxide emissions from internal combustion engine exhaust gases when they are brought into contact with the catalyst even when hydrocarbon concentration in exhaust gases varies, exhaust gas purification device using the same and method for purification of exhaust gases.

Abstract: An exhaust gas purification catalyst, which is suitable as a Three Way Catalyst for efficiently purifying carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) in exhaust gas discharged from a gasoline automobile, an exhaust gas purification apparatus using the same and an exhaust gas purification method. It is provided by an exhaust gas purification catalyst, wherein catalyst components for purifying hydrocarbons (HC), carbon monoxide (CO) and nitrogen oxides (NOx) contained in exhaust gas are coated onto a honeycomb type structure as a catalyst composition layer, characterized in that the catalyst components comprise an activated metal (A), a heat resistant inorganic oxide (B) and a cerium-zirconium composite oxide (c) containing a pyrochlore phase in a crystal structure, in the same catalyst composition layer, and the activated metal (A) is a palladium and a rhodium and does not contain a platinum.

Abstract: The present invention provides a cerium oxide-zirconium oxide-based mixed oxide having superior platinum dispersibility and a suitable OSC, and a simple production process thereof. The cerium oxide-zirconium oxide-based mixed oxide comprises cerium oxide and zirconium oxide, wherein (1) the weight ratio of CeO2:ZrO2 is 60:40 to 90:10, and (2) the cerium oxide and the zirconium oxide are present as a mixture, the zirconium oxide being composed of a solid solution in which tetragonal or cubic zirconium oxide contains cerium.

Abstract: This invention relates to a cerium—zirconium-base composite oxide, which is useful, e.g., for the purification of exhaust gas discharged from combustion engines such as internal combustion engines and boilers and can release a high level of oxygen in a low temperature region, a method for producing the same, an oxygen storage/release component using the same, an exhaust gas purification catalyst, and an exhaust gas purification method. The cerium—zirconium-base composite oxide satisfies requirements (1) that the oxygen release initiation temperature is 380° C. or below, (2) that the oxygen release amount is not less than 485 ?mol/g, and further (3) that the oxygen release amount at 400° C. is not less than 15 ?mol/g.

Abstract: The present invention relates to a nickel oxide-stabilized zirconia composite in which nickel oxide is dispersed uniformly, a process for readily producing the composite oxide, and an anode for a solid oxide fuel cell having excellent output characteristics. More specifically, the present invention provides a nickel oxide-stabilized zirconia composite that is produced by sintering a mixture of nickel hydroxide and/or nickel carbonate and a hydroxide of stabilized zirconium.

Abstract: An exhaust gas purification catalyst, which is suitable as a Three way catalyst for efficiently purifying carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) in exhaust gas discharged from a gasoline automobile, an exhaust gas purification apparatus using the same and an exhaust gas purification method. <The Upper Layer> A catalyst composition having an activated metal (A), a heat resistant inorganic oxide (B) and a cerium-zirconium-type composite oxide (C) containing a pyrochlore phase in a crystal structure, wherein the activated metal (A) is rhodium. <The Lower Layer> A catalyst composition having an activated metal (A), a heat resistant inorganic oxide (B) and a cerium-containing oxide (C?) having a cubic crystal and/or a tetragonal crystal as a major crystal structure, wherein the activated metal (A) is palladium, or palladium and platinum.

Abstract: The present invention provides a porous zirconium powder having improved heat resistance of total pore volume, and a simple production method thereof. More specifically, the present invention provides: (1) a porous zirconium powder in which total pore volume following heat treatment for three hours at 1000° C. is at least 0.75 ml/g, and total volume of pores having a diameter of 10 to 100 nm following heat treatment for three hours at 1000° C. is at least 30% of the total pore volume, and (2) a production method of a porous zirconia powder comprising: forming a basic zirconium sulfate by adding a sulfating agent to a zirconium salt solution; forming zirconium hydroxide by neutralizing the basic zirconium sulfate; and heat-treating the zirconium hydroxide, wherein, when adding the sulfating agent to the zirconium salt solution, the sulfating agent is added to the zirconium salt solution having a temperature of 100° C. or higher in an autoclave.

Abstract: The present invention provides a zirconia-ceria-yttria-based mixed oxide having a stable crystal structure after 12 hours of heat treatment at 1100° C. under a reducing atmosphere, and a process for producing the mixed oxide.

Abstract: The present invention provides a cerium oxide-zirconium oxide-based mixed oxide having superior platinum dispersibility and a suitable OSC, and a simple production process thereof. The cerium oxide-zirconium oxide-based mixed oxide comprises cerium oxide and zirconium oxide, wherein (1) the weight ratio of CeO2:ZrO2 is 60:40 to 90:10, and (2) the cerium oxide and the zirconium oxide are present as a mixture, the zirconium oxide being composed of a solid solution in which tetragonal or cubic zirconium oxide contains cerium.

Abstract: This invention relates to a cerium-zirconium-base composite oxide, which is useful, e.g., for the purification of exhaust gas discharged from combustion engines such as internal combustion engines and boilers and can release a high level of oxygen in a low temperature region, a method for producing the same, an oxygen storage/release component using the same, an exhaust gas purification catalyst, and an exhaust gas purification method. The cerium-zirconium-base composite oxide satisfies requirements (1) that the oxygen release initiation temperature is 380° C. or below, (2) that the oxygen release amount is not less than 485 ?mol/g, and further (3) that the oxygen release amount at 400° C. is not less than 15 ?mol/g.

Abstract: This invention provides a colored zirconia-based sintered body, mainly composed of zirconia containing a stabilizer, which contains alumina and nickel spinel, and has a novel color tone, and a method for manufacturing such a zirconia-based sintered body. The colored zirconia-based sintered body is applicable not only to a highly decorative product such as a watch, but also to knives, tweezers, machining jigs and holding jigs for electronic parts, and sliding members.

Abstract: This invention provides a colored zirconia-based sintered body, mainly composed of zirconia containing a stabilizer, which contains alumina and nickel spinel, and has a novel color tone, and a method for manufacturing such a zirconia-based sintered body. The colored zirconia-based sintered body is applicable not only to a highly decorative product such as a watch, but also to knives, tweezers, machining jigs and holding jigs for electronic parts, and sliding members.