Abstract: A particulate material with a composition expressed by MaAlbXc in which “M” includes one or more elements selected from the group consisting of Ti, V, Cr, Zr, Nb, Mo, Hf and Ta and “X” includes C or one or more chemical structures selected from the group consisting of C(1.0?x)Nx (where “x” is 0<“x”?1.0), wherein: “a” is two or three; “b” is more than 0.02; and “c” is from 0.8 to 1.2 when “a” is two; or “c” is from 1.8 to 2.6 when “a” is 3. The particulate material has thicknesses whose average value is from 3.5 nm or more to 20 nm or less, and sizes, [{(longer sides)+(shorter sides)}/2], whose average value is from 50 nm or more to 300 nm or less.

Abstract: A particulate material with a composition expressed by Ti2Alx(C(1-y)Ny)z (where “x” is more than 0.02, “y” is 0<“y”<1.0, and “z” is from 0.8 to 1.20), the particulate material comprising layers including gap layers providing an interlayer distance of from 0.59 nm to 0.70 nm within a crystal lattice; and/or with another composition expressed by Ti3Alx(C(1-y)Ny)z (where “x” is more than 0.02, “y” is 0<“y”<1.0, and “z” is from 1.80 to 2.60), the particulate material comprising layers including gap layers providing an interlayer distance of from 0.44 nm to 0.55 nm within a crystal lattice.

Abstract: A ceria-zirconia-based composite oxide containing a composite oxide of ceria and zirconia is provided, in which primary particles having a particle diameter of 1.5 to 4.5 ?m account for, on a particle number basis, at least 50% of all primary particles in the ceria-zirconia-based composite oxide, and the molar ratio of cerium to zirconium in the ceria-zirconia-based composite oxide is between 43:57 and 55:45.

Abstract: A particulate material with a composition expressed by Ti2Alx (C(1-y)Ny)z (where “x” is more than 0.02, “y” is 0<“y”<1.0, and “z” is from 0.8 to 1.20), the particulate material comprising layers including gap layers providing an interlayer distance of from 0.59 nm to 0.70 nm within a crystal lattice; and/or with another composition expressed by Ti3Alx(C(1-y)Ny)z (where “x” is more than 0.02, “y” is 0<“y”<1.0, and “z” is from 1.80 to 2.60), the particulate material comprising layers including gap layers providing an interlayer distance of from 0.44 nm to 0.55 nm within a crystal lattice.

Abstract: A particulate material with a composition expressed by MaAlbXc in which “M” includes one or more elements selected from the group consisting of Ti, V, Cr, Zr, Nb, Mo, Hf and Ta and “X” includes C or one or more chemical structures selected from the group consisting of C(1.0?x)Nx (where “x” is 0<“x”?1.0), wherein: “a” is two or three; “b” is more than 0.02; and “c” is from 0.8 to 1.2 when “a” is two; or “c” is from 1.8 to 2.6 when “a” is 3. The particulate material has thicknesses whose average value is from 3.5 nm or more to 20 nm or less, and sizes, [{(longer sides)+(shorter sides)}/2], whose average value is from 50 nm or more to 300 nm or less.

Abstract: The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H2S emissions. The object is solved by an exhaust gas purifying catalyst in which the lower layer of the catalyst coating layer comprises a ceria-zirconia composite oxide having a pyrochlore-type ordered array structure, in which the ceria-zirconia composite oxide contains at least one additional element selected from the group consisting of praseodymium, lanthanum, and yttrium at 0.5 to 5.0 mol % in relation to the total cation amount, and the molar ratio of (cerium+additional element):(zirconium) is within the range from 43:57 to 48:52.

Abstract: The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H2S emissions. The object is solved by an exhaust gas purifying catalyst in which the top layer of a catalyst coating layer comprises a ceria-zirconia composite oxide having a pyrochlore-type ordered array structure, in which the ceria-zirconia composite oxide contains at least one additional element selected from the group consisting of praseodymium, lanthanum, and yttrium at 0.5 to 5.0 mol % in relation to the total cation amount, and the molar ratio of (cerium+additional element):(zirconium) is within the range from 43:57 to 48:52.

Abstract: The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H2S emissions. The object is solved by an exhaust gas purifying catalyst in which the lower layer of the catalyst coating layer comprises a ceria-zirconia composite oxide having a pyrochlore-type ordered array structure, in which the ceria-zirconia composite oxide contains at least one additional element selected from the group consisting of praseodymium, lanthanum, and yttrium at 0.5 to 5.0 mol % in relation to the total cation amount, and the molar ratio of (cerium+additional element):(zirconium) is within the range from 43:57 to 48:52.

Abstract: An oxygen storage/release material includes: a ceria-zirconia composite oxide porous body that has at least one ordered phase of a pyrochlore phase and a ? phase, and that has a central pore diameter of 70 nm to 1 ?m as measured by a mercury penetration method, and in which a cumulative pore volume of pores that each have a pore diameter in the range of 0.5 times to 2 times the central pore diameter is 40% or more of the cumulative pore volume of pores that each have a pore diameter in the range of 10 nm to 10 ?m as measured by the mercury penetration method.

Abstract: The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H2S emissions. The object is solved by an exhaust gas purifying catalyst in which the top layer of a catalyst coating layer comprises a ceria-zirconia composite oxide having a pyrochlore-type ordered array structure, in which the ceria-zirconia composite oxide contains at least one additional element selected from the group consisting of praseodymium, lanthanum, and yttrium at 0.5 to 5.0 mol % in relation to the total cation amount, and the molar ratio of (cerium+additional element):(zirconium) is within the range from 43:57 to 48:52.

Abstract: The object of the present invention is to provide a high-performance exhaust gas purifying catalyst that can achieve oxygen absorption/release capacity and NOx purification performance. The object is solved by an exhaust gas purifying catalyst, which comprises a ceria-zirconia composite oxide having a pyrochlore-type ordered array structure in the upstream part of the catalyst coating layer, in which the ceria-zirconia composite oxide contains at least one additional element selected from the group consisting of praseodymium, lanthanum, and yttrium at 0.5 to 5.0 mol % of the total cation amount, and has a molar ratio of (cerium+the additional element):(zirconium) of 43:57 to 48:52.

Abstract: A ceria-zirconia composite oxide includes at least one of lanthanum, yttrium, and praseodymium. A rate of a total content of the at least one rare earth element to a total content of cerium and zirconium is 0.1 at % to 4.0 at %. A content of the rare earth element present in near-surface regions, which are at a distance of less than 50 nm from surfaces of primary particles of the ceria-zirconia composite oxide, accounts for 90 at % or more of the total content of the rare earth element. An average particle size of the primary particles of the ceria-zirconia composite oxide is 2.2 ?m to 4.5 ?m. After a predetermined durability test, the intensity ratio I(14/29) of a diffraction line at 2?=14.5° to a diffraction line at 2?=29° and the intensity ratio I(28/29) of a diffraction line at 2?=28.5° to the diffraction line at 2?=29° respectively satisfy the following conditions: I(14/29)?0.02, and I(28/29)?0.08.

Abstract: The object of the present invention is to provide a high-performance exhaust gas purifying catalyst that can achieve oxygen absorption/release capacity and NOx purification performance. The object is solved by an exhaust gas purifying catalyst, which comprises a ceria-zirconia composite oxide having a pyrochlore-type ordered array structure in the upstream part of the catalyst coating layer, in which the ceria-zirconia composite oxide contains at least one additional element selected from the group consisting of praseodymium, lanthanum, and yttrium at 0.5 to 5.0 mol % of the total cation amount, and has a molar ratio of (cerium+the additional element):(zirconium) of 43:57 to 48:52.

Abstract: A ceria-zirconia-based composite oxide containing a composite oxide of ceria and zirconia is provided, in which primary particles having a particle diameter of 1.5 to 4.5 ?m account for, on a particle number basis, at least 50% of all primary particles in the ceria-zirconia-based composite oxide, and the molar ratio of cerium to zirconium in the ceria-zirconia-based composite oxide is between 43:57 and 55:45.

Abstract: An oxygen storage/release material includes: a ceria-zirconia composite oxide porous body that has at least one ordered phase of a pyrochlore phase and a ? phase, and that has a central pore diameter of 70 nm to 1 ?m as measured by a mercury penetration method, and in which a cumulative pore volume of pores that each have a pore diameter in the range of 0.5 times to 2 times the central pore diameter is 40% or more of the cumulative pore volume of pores that each have a pore diameter in the range of 10 nm to 10 ?m as measured by the mercury penetration method.

Abstract: A ceria-zirconia-based composite oxide containing a composite oxide of ceria and zirconia is provided, in which primary particles having a particle diameter of 1.5 to 4.5 ?m account for, on a particle number basis, at least 50% of all primary particles in the ceria-zirconia-based composite oxide, and the molar ratio of cerium to zirconium in the ceria-zirconia-based composite oxide is between 43:57 and 55:45.

Abstract: The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H2S emissions. The object is solved by an exhaust gas purifying catalyst in which the lower layer of the catalyst coating layer comprises a ceria-zirconia composite oxide having a pyrochlore-type ordered array structure, in which the ceria-zirconia composite oxide contains at least one additional element selected from the group consisting of praseodymium, lanthanum, and yttrium at 0.5 to 5.0 mol % in relation to the total cation amount, and the molar ratio of (cerium+additional element):(zirconium) is within the range from 43:57 to 48:52.

Abstract: Iron compound particles comprise a ?-FeOOH crystal phase and a metal element other than Fe with which the ?-FeOOH crystal phase is doped, wherein the metal element other than Fe is at least one metal element selected from the group consisting of elements of Al as well as 3d and 4d transition metals belonging to periodic table Groups 4 to 12 other than Fe, an atomic ratio of the metal element other than Fe to the Fe element (metal element other than Fe/Fe element) is 0.001 to 0.5, and the iron compound particles satisfy at least one of the following requirements (A) and (B): (A) having a crystallite diameter of 1 to 60 nm when measured by X-ray diffraction; and (B) having an average particle diameter of 1 to 600 nm when measured by dynamic light scattering in a solvent.

Abstract: A ceria-zirconia-based composite oxide including a composite oxide containing ceria and zirconia, wherein the ceria-zirconia-based composite oxide contains at least one member selected from the group consisting of praseodymium, lanthanum, and yttrium in an amount of 0.5 to 5.0 mol % relative to a total amount of the cations contained in the ceria-zirconia-based composite oxide, where the ratio of the content of both cerium and the at least one member selected from the group consisting of praseodymium, lanthanum, and yttrium in the ceria-zirconia-based composite oxide to the content of zirconium therein ([cerium and the at least one member selected from the group consisting of praseodymium, lanthanum, and yttrium]:[zirconium]) is in the range of 43:57 to 48:52 by mole ratio.

Abstract: The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H2S emissions. The object is solved by an exhaust gas purifying catalyst in which the top layer of a catalyst coating layer comprises a ceria-zirconia composite oxide having a pyrochlore-type ordered array structure, in which the ceria-zirconia composite oxide contains at least one additional element selected from the group consisting of praseodymium, lanthanum, and yttrium at 0.5 to 5.0 mol % in relation to the total cation amount, and the molar ratio of (cerium+additional element):(zirconium) is within the range from 43:57 to 48:52.