Abstract: A catalyst for purification of exhaust gas in which Pd-based nanoparticles and ceria nanoparticles are supported on a composite metal oxide support containing alumina, ceria, and zirconia, wherein a molar ratio (Ce/Pd) of Ce and Pd supported on the support is 1 to 8, a proximity ? between Pd and Ce is 0.15 to 0.50, wherein the proximity ? is determined, based on Pd and Ce distribution maps in an element mapping image of energy dispersive X-ray analysis, by the following formula (1): ? = ? j = 0 N - 1 ? ? i = 0 M - 1 ? ( ( I ? ( i , j ) - I ave ) ? ( T ? ( i , j ) - T ave ) ) ? j = 0 N - 1 ? ? i = 0 M - 1 ? ( I ? ( i , j ) - I ave ) 2 - ? j = 0 N - 1 ? ? i = 0 M - 1 ? ( T ? ( i , j ) - T ave ) 2 , ( 1 ) a Pd dispersity after a heat-resistance test at 1050° C. for 25 hours is 0.8% or more.

Abstract: A catalyst for purification of exhaust gas in which Pd-based nanoparticles and ceria nanoparticles represented by CeO2-x, (0?x<0.5) are supported on a composite metal oxide support containing alumina, ceria, and zirconia, wherein a molar ratio (Ce/Pd) of Ce and Pd supported on the support is 1 to 8, a proximity ? between Pd and Ce is 0.15 to 0.50, wherein the proximity ? is determined, based on Pd and Ce distribution maps in an element mapping image of energy dispersive X-ray analysis, by the following formula (1) ? = ? j = 0 N - 1 ? ? i = 0 M - 1 ? ( ( I ? ( i , j ) - I ave ) ? ( T ? ( i , j ) - T ave ) ) ? j = 0 N - 1 ? ? i = 0 M - 1 ? ( I ? ( i , j ) - I ave ) 2 - ? j = 0 N - 1 ? ? i = 0 M - 1 ? ( T ? ( i , j ) - T ave ) 2 , ( 1 ) and a Pd dispersity after a heat-resistance test is 0.

Abstract: A core-shell support, comprising: a core which comprises at least one oxygen storage/release material selected from the group consisting of ceria-zirconia based solid solutions and alumina-doped ceria-zirconia based solid solutions; and a shell which comprises a rare earth-zirconia based composite oxide represented by a composition formula: (Re1-xCex)2Zr2O7+x (where Re represents a rare earth element, and x represents a number of 0.0 to 0.8) and with which an outside of the core is coated, the rare earth-zirconia based composite oxide comprising crystal particles having a pyrochlore structure, and the rare earth-zirconia based composite oxide having an average crystallite diameter of 3 to 9 nm.

Abstract: A core-shell oxide material comprises: a core which comprises a ceria-zirconia based solid solution powder having at least one ordered phase of a pyrochlore phase and a ? phase; and a shell which comprises an alumina based oxide disposed on at least a portion of a surface of the core.

Abstract: A core-shell oxide material comprises: a core which comprises a ceria-zirconia based solid solution powder having at least one ordered phase of a pyrochlore phase and a ? phase; and a shell which comprises an alumina based oxide disposed on at least a portion of a surface of the core.

Abstract: A catalyst support for purification of exhaust gas includes a porous composite metal oxide, the porous composite metal oxide containing alumina, ceria, and zirconia and having an alumina content ratio of from 5 to 80% by mass, wherein after calcination in the air at 1100° C. for 5 hours, the porous composite metal oxide satisfies a condition such that standard deviations of content ratios (as at % unit) of aluminum, cerium and zirconium elements are each 19 or less with respect to 100 minute areas (with one minute area being 300 nm in length×330 nm in width) of the porous composite metal oxide, the standard deviation being determined by energy dispersive X-ray spectroscopy using a scanning transmission electron microscope equipped with a spherical aberration corrector.

Abstract: The object of the present invention is to provide an oxygen storage material used for an exhaust gas purifying catalyst that is superior in stability at high temperatures. The composite oxide material of the invention comprises crystalline particles of a ceria-zirconia composite oxide with a pyrochlore structure and crystals of a lanthana-zirconia composite oxide with a pyrochlore structure existing on the particle surface, in which the crystals of the lanthana-zirconia composite oxide is solidly dissolved in at least a part of the surface of the crystalline particles of ceria-zirconia composite oxide. In the composite oxide material according to the present invention, the pyrochlore structure of the ceria-zirconia composite oxide is stabilized, and the decrease in oxygen storage capacity resulting from phase shift into the fluorite structure is suppressed.

Abstract: A catalyst support for purification of exhaust gas includes a porous composite metal oxide, the porous composite metal oxide containing alumina, ceria, and zirconia and having an alumina content ratio of from 5 to 80% by mass, wherein after calcination in the air at 1100° C. for 5 hours, the porous composite metal oxide satisfies a condition such that standard deviations of content ratios (as at % unit) of aluminum, cerium and zirconium elements are each 19 or less with respect to 100 minute areas (with one minute area being 300 nm in length×330 nm in width) of the porous composite metal oxide, the standard deviation being determined by energy dispersive X-ray spectroscopy using a scanning transmission electron microscope equipped with a spherical aberration corrector.