Abstract: A satisfactory oxygen storage material and a method for producing it are provided. The oxygen storage material comprises zirconia particles with a ceria-zirconia complex oxide supported on the zirconia particles. The ceria-zirconia complex oxide includes a pyrochlore phase and has a mean crystallite diameter of 10 nm to 22.9 nm.

Abstract: [SUMMARY] [PURPOSE] To provide a satisfactory oxygen storage material and a method for producing it. [SOLUTION MEANS] An oxygen storage material comprising: zirconia particles and a ceria-zirconia complex oxide supported on them, wherein the ceria-zirconia complex oxide includes a pyrochlore phase, and has a mean crystallite diameter of 10 nm to 22.9 nm.

Abstract: A catalyst for purification of exhaust gases, comprising a support substrate, a catalyst carrier layer formed on the support substrate and catalyst ingredients loaded on the catalyst carrier layer, wherein the catalyst carrier layer comprises alumina, cerium oxide, zirconium oxide and at least one oxide of rare earth element except cerium and lanthanum, and at least a part of cerium oxide, zirconium oxide and oxide of rare earth element except cerium and lanthanum is present in the form of composite oxide and/or solid solution. The catalyst for purification of exhaust gases is capable of purifying exhaust gases containing carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx).

Abstract: A catalyst for purification of exhaust gases comprising: a support substrate; an active alumina coating layer comprising at least one of nickel oxide and cobalt oxide formed on the surface of the support substrate; a composite oxide comprising cerium oxide and zirconium oxide formed in the active alumina coating layer; and noble metal catalyst ingredients comprising at least one of platinum, palladium and rhodium loaded on the active alumina coating layer. The catalyst offers a decreased hydrogen sulfide H.sub.2 S emission and conversion ratios for hydrocarbon (HC), carbon monoxide (CO), and nitrogen oxides (NOx) equivalent to or superior to those of conventional catalysts.

Abstract: A catalyst for the purification of exhaust gases comprising a catalyst carrier layer and catalyst ingredients carried thereon, is capable of enhancing the purification property by suppressing the growth of cerium oxide particles and preventing the formation of LaAlO.sub.3. This catalyst has two composition types. One is a binary composition catalyst comprising oxides of cerium and zirconium in the catalyst carrier layer and the other is a ternary composition catalyst comprising oxides of cerium, zirconium and lanthanum in the catalyst carrier layer.

Abstract: A catalyst for purifying exhaust gases comprises: a perovskite-type complex oxide represented by the general formula Ln.sub.1-x A.sub.x MO.sub.3, wherein Ln represents at least one rare earth metal, A presents at least one alkaline earth metal and M represents at least one transition metal, and 0<x<1; at least one heat resistant complex oxide; and at least one precious metal. The heat resistant complex oxide is one of ABO.sub.3, LnAlO.sub.3 or Ln.sub.2 B.sub.2 O.sub.7, wherein A represents at least one alkaline earth metal, B represents at least one of Ti, Zr and Hf, and Ln represents at least one rare earth metal, and the precious metal is at least one of Pt, Pd, Rh, Ir, Ru and Os. The catalyst is usable as a temperature of 900.degree. C. or above without sintering or reduction of a catalytic activity.

Abstract: An alumina catalyst support stable at high temperatures comprises transformative alumina having a purity not less than 99.95% impregnated with lanthanum in an amount of 1.5 to 6 wt % based on the weight of the alumina. The alumina catalyst support has a surface area of at least 60 m.sup.2 /g after heating at 1200.degree. C. for 5 hours.