Abstract: An object of the present invention is to provide a cerium oxide (CeO2)-zirconium oxide (ZrO2)-aluminum oxide (Al2O3)-based complex oxide having an improved heat resistance and a method of producing the complex oxide, and the present invention provides a complex oxide containing a cerium element, a zirconium element, an aluminum element, and optionally a rare earth metal element other than a cerium element, wherein a specific surface area measured by a BET method after heat treatment in an air atmosphere at 1000° C. for 25 hours is 60 m2/g or more, and a method of producing the complex oxide.

Abstract: A composition for exhaust gas purification containing Y—Mn—O and Al2O3 and having a specific surface area (SSA) retention satisfying inequality (1) SSA retention (%) >?61.54×(Y—Mn—O ratio)+75.55 and inequality (2) SSA retention (%) >45 (2), where SSA retention is represented by (SSA after aging)/(initial SSA)×100 (%). The SSA after aging and the initial SSA are as defined in the description. The Y—Mn—O ratio is a mass ratio of Y—Mn—O to the sum of Y—Mn—O and Al2O3 in the composition for exhaust gas purification, being represented by Y—Mn—O/(Y—Mn—O+Al2O3).

Abstract: A composition for exhaust gas purification containing Y—Mn—O and Al2O3 and having a specific surface area (SSA) retention satisfying inequality (1) SSA retention (%) >?61.54×(Y—Mn—O ratio)+75.55 and inequality (2) SSA retention (%) >45 (2), where SSA retention is represented by (SSA after aging)/(initial SSA)×100 (%). The SSA after aging and the initial SSA are as defined in the description. The Y—Mn—O ratio is a mass ratio of Y—Mn—O to the sum of Y—Mn—O and Al2O3 in the composition for exhaust gas purification, being represented by Y—Mn—O/(Y—Mn—O+Al2O3).

Abstract: An exhaust gas purifying composition of the present invention contains zeolite that is BEA zeolite having an SiO2/Al2O3 molar ratio of greater than 25 and 600 or less and containing phosphorus. Furthermore, the exhaust gas purifying composition preferably contains zirconium in addition to phosphorus. Furthermore, the zeolite has an SiO2/Al2O3 molar ratio of from 30 to 150. The present invention provides an exhaust gas purifying composition having excellent HC adsorbability for exhaust gas purification in internal combustion engines such as gasoline engines.

Abstract: The present invention provides an exhaust gas purifying composition containing BEA zeolite containing phosphorus, wherein an amount of phosphorus is such that a molar ratio thereof with respect to Al in the zeolite is 0.5 or greater, and a maintaining factor RS of a specific surface area of the exhaust gas purifying composition after heating at 980° C. for 25 hours is 35% or greater. Furthermore, the present invention also provides an exhaust gas purifying composition containing phosphorus-containing zeolite, wherein an amount of phosphorus is such that a molar ratio thereof with respect to Al in the zeolite is from 0.5 to 8, and a maintaining factor Rd of a crystallite diameter after heating at 980° C. for 25 hours is 50% or greater. The exhaust gas purifying composition of the present invention has excellent HC purifiability for exhaust gas purification in internal combustion engines such as gasoline engines.

Abstract: The present invention provides an exhaust gas purifying composition containing BEA zeolite containing phosphorus, wherein an amount of phosphorus is such that a molar ratio thereof with respect to Al in the zeolite is 0.5 or greater, and a maintaining factor RS of a specific surface area of the exhaust gas purifying composition after heating at 980° C. for 25 hours is 35% or greater. Furthermore, the present invention also provides an exhaust gas purifying composition containing phosphorus-containing zeolite, wherein an amount of phosphorus is such that a molar ratio thereof with respect to Al in the zeolite is from 0.5 to 8, and a maintaining factor Rd of a crystallite diameter after heating at 980° C. for 25 hours is 50% or greater. The exhaust gas purifying composition of the present invention has excellent HC purifiability for exhaust gas purification in internal combustion engines such as gasoline engines.

Abstract: The invention relates to a catalyst composition using other metals different from precious metals as a catalytically active component and is to propose a novel catalyst composition for exhaust gas purification which has excellent catalytic activity, in particular, excellent treatment activity of HC even after a thermal durability treatment. The invention is to propose a catalyst composition for exhaust gas purification comprising catalyst particles having a constitution in which Cu and a transition metal A including at least one of Cr, Fe, Mn, Co, Ni, Zr, and Ag are supported on ceria (CeO2) particles and a catalyst using the same.

Abstract: An exhaust gas purifying composition of the present invention contains zeolite that is BEA zeolite having an SiO2/Al2O3 molar ratio of greater than 25 and 600 or less and containing phosphorus. Furthermore, the exhaust gas purifying composition preferably contains zirconium in addition to phosphorus. Furthermore, the zeolite has an SiO2/Al2O3 molar ratio of from 30 to 150. The present invention provides an exhaust gas purifying composition having excellent HC adsorbability for exhaust gas purification in internal combustion engines such as gasoline engines.

Abstract: An exhaust gas purification device is equipped with: an NOx purification unit disposed in exhaust gas piping of an engine supporting an NOx storage catalyst (NSC); a catalyzed soot filter (CSF) disposed downstream of the NOx purification unit supporting a particulate combustion catalyst causing captured particulates to combust; and an electronic control unit (ECU) which controls exhaust gas flowing into the NSC to be rich and which, by raising the temperature of the NSC, acts as a regeneration device that causes sulfur components captured in the NSC to be desorbed. The particulate combustion catalyst is provided where Ag and Pd have been alloyed on an Al2O3 carrier; the quantity of Ag supported by the Al2O3 carrier is 1.2-2.5 g/L; the quantity of Pd supported by the Al2O3 carrier is 0.7 g/L or less; and the ratio Ag/Pd of the Ag support quantity to the Pd support quantity is 1.7-8.3.

Abstract: An exhaust gas purification device is equipped with: an NOx purification unit disposed in exhaust gas piping of an engine supporting an NOx storage catalyst (NSC); a catalyzed soot filter (CSF) disposed downstream of the NOx purification unit supporting a particulate combustion catalyst causing captured particulates to combust; and an electronic control unit (ECU) which controls exhaust gas flowing into the NSC to be rich and which, by raising the temperature of the NSC, acts as a regeneration device that causes sulfur components captured in the NSC to be desorbed. The particulate combustion catalyst is provided where Ag and Pd have been alloyed on an Al2O3 carrier; the quantity of Ag supported by the Al2O3 carrier is 1.2-2.5 g/L; the quantity of Pd supported by the Al2O3 carrier is 0.7 g/L or less; and the ratio Ag/Pd of the Ag support quantity to the Pd support quantity is 1.7-8.3.

Abstract: The invention relates to a catalyst composition using other metals different from precious metals as a catalytically active component and is to propose a novel catalyst composition for exhaust gas purification which has excellent catalytic activity, in particular, excellent treatment activity of HC even after a thermal durability treatment. The invention is to propose a catalyst composition for exhaust gas purification comprising catalyst particles having a constitution in which Cu and a transition metal A including at least one of Cr, Fe, Mn, Co, Ni, Zr, and Ag are supported on ceria (CeO2) particles and a catalyst using the same.

Abstract: A catalyst for exhaust gas purification having superior exhaust gas purification performance is provided. Disclosed is a catalyst containing, as a catalyst support, a composite phosphate containing yttrium and phosphorus and having a composition ratio of yttrium to phosphorus (Y/P) of greater than 1 as a molar ratio.

Abstract: A catalyst for exhaust gas purification having superior exhaust gas purification performance is provided. Disclosed is a catalyst containing, as a catalyst support, a composite phosphate containing yttrium and phosphorus and having a composition ratio of yttrium to phosphorus (Y/P) of greater than 1 as a molar ratio.