摘要:
An object of the present invention is to provide a catalyst composition containing a perovskite-type composite oxide which exhibits a satisfactory catalytic performance over a long time even in a high temperature atmosphere and has a stable quality in which Rh and/or Pt dissolves to form a solid solution at a high rate.To achieve the object described above, in the present invention the catalyst composition is prepared to comprise an Rh-containing perovskite-type composite oxide represented by the following general formula (I) and/or a Pt-containing perovskite-type composite oxide represented by the following general formula (II) and a thermostable oxide optionally containing a noble metal. A1xA2wB11−(y+z)B2yRhzO3±δ (I) A3rA4sB31−(t+u)B4tPtuO3±δ′ (II)
摘要:
To provide a catalyst composition containing a novel perovskite-type composite oxide which permits reversible entrance and exit of noble metals, a catalyst composition is prepared so as to contain a perovskite-type composite oxide represented by the general formula (1): AxA′wByB′(1-y-z)NzO3±σ (1) (wherein A represents at least one element selected from alkaline earth metals; A′ represents at least one element selected from rare earth elements; B represents a tetravalent rare earth element; B′ represents at least one element selected from transition elements (excluding tetravalent rare earth elements, Rh, Pd and Pt); N represents at least one element selected from Rh, Pd and Pt; x and w represent an atomic ratio satisfying the following relations: 0.8≦x+w≦1.3 (0.8≦x≦1.3, 0≦w≦0.4); y represents an atomic ratio satisfying the following relation: 0
摘要翻译:为了提供一种催化剂组合物,其含有允许贵金属的可逆入口和退出的新型钙钛矿型复合氧化物,制备催化剂组合物以含有由通式(1)表示的钙钛矿型复合氧化物:<β -line-formula description =“In-line Formulas”end =“lead”?> AxA'wByB'(1-yz)NzO3±sigma(1)<?in-line-formula description =“In-line Formulas”end =“尾”→(其中A表示选自碱土金属中的至少一种元素; A'表示选自稀土元素中的至少一种元素; B表示四价稀土元素; B'表示选自以下的至少一种元素: 过渡元素(不含四价稀土元素,Rh,Pd和Pt); N表示选自Rh,Pd和Pt中的至少一种元素; x和w表示满足以下关系的原子比:0.8 <= x + w < 1.3(0.8 <= x <= 1.3,0 <= w <= 0.4); y表示满足以下关系的原子比:0
摘要:
An exhaust gas-purifying catalyst (1) contains a rare-earth element, an alkaline-earth element, zirconium and a precious metal, wherein an atomic ratio of the alkaline-earth element with respect to a sum of the rare-earth element and the zirconium is 10 atomic % or more, a part of the rare-earth element and a part of zirconium form a composite oxide with at least a part of the alkaline-earth element, and the composite oxide and a part of the precious metal form a solid solution.
摘要:
Provided is a catalyst with a noble metal efficiently supported on the surfacemost thereof. A composite oxide-containing layer is formed on a catalyst carrier so as to contain a perovskite-type composite oxide represented by the following general formula (1) and an other composite oxide, and a noble metal layer is further formed on the catalyst carrier so as to be supported on the surfacemost of the catalyst carrier by immersing the catalyst carrier formed with the composite oxide-containing layer in an aqueous noble metal salt solution to impregnate the catalyst carrier with the aqueous noble metal salt solution: AxByO3±δ (1) (wherein A represents at least one element selected from rare earth elements and alkaline earth metals; B represents at least one element selected from transition elements (excluding rare earth elements); x represents an atomic ratio of less than 1; y represents an atomic ratio of 1.0; and δ represents an oxygen excess or an oxygen deficiency.)
摘要:
An exhaust gas-purifying catalyst is less prone to cause a decrease in its activity even when used in a high temperature atmosphere containing oxygen at a high concentration. The exhaust gas-purifying catalyst includes a composite oxide and Pd or a second solid solution of a composite and Rh and/or Pt. The first and second solid solutions have perovskite structure and are represented by ABO3 and CDO3, respectively. The composite oxide catalyst is supported by a composite oxide support including a composite oxide of spinel structure represented by EF2O4 or a composite oxide represented by GAl12O19. A and B represent a rare-earth element and a transition element, respectively. C and G represent an alkaline-earth element. D represents one or more of Ti, Zr, Hf and Ce. E represents an alkaline-earth element and/or a transition element. F represents one or more of Al, Mg and transition elements.
摘要:
Provided is a catalyst with a noble metal efficiently supported on the surfacemost thereof. A composite oxide-containing layer is formed on a catalyst carrier so as to contain a perovskite-type composite oxide represented by the following general formula (1) and an other composite oxide, and a noble metal layer is further formed on the catalyst carrier so as to be supported on the surfacemost of the catalyst carrier by immersing the catalyst carrier formed with the composite oxide-containing layer in an aqueous noble metal salt solution to impregnate the catalyst carrier with the aqueous noble metal salt solution: AxByO3±δ (1) (wherein A represents at least one element selected from rare earth elements and alkaline earth metals; B represents at least one element selected from transition elements (excluding rare earth elements); x represents an atomic ratio of less than 1; y represents an atomic ratio of 1.0; and δ represents an oxygen excess or an oxygen deficiency.)
摘要:
An exhaust gas-purifying catalyst (1) contains a rare-earth element, an alkaline-earth element, zirconium and a precious metal, wherein an atomic ratio of the alkaline-earth element with respect to a sum of the rare-earth element and the zirconium is 10 atomic % or more, a part of the rare-earth element and a part of zirconium form a composite oxide with at least a part of the alkaline-earth element, and the composite oxide and a part of the precious metal form a solid solution.
摘要:
An excellent oxygen storage capacity is achieved even in the case used for a long period of time under high temperature conditions. An oxygen storage material contains a first particle made of a composite oxide of cerium and zirconium or a composite oxide of cerium, a rare-earth element other than cerium and zirconium, a second particle including a composite oxide of a rare-earth element, an alkaline-earth element and zirconium, and a precious metal. A part of the precious metal forms a solid solution with the composite oxide included in the second particle.
摘要:
An excellent oxygen storage capacity is achieved even in the case used for a long period of time under high temperature conditions. An oxygen storage material contains a first particle made of a composite oxide of cerium and zirconium or a composite oxide of cerium, a rare-earth element other than cerium and zirconium, a second particle including a composite oxide of a rare-earth element, an alkaline-earth element and zirconium, and a precious metal. A part of the precious metal forms a solid solution with the composite oxide included in the second particle.
摘要:
To provide a perovskite-type composite oxide which has stable quality in which a solid solution of Pd is formed at a high rate, a method for producing the perovskite-type composite oxide, and a catalyst composition containing the perovskite-type composite oxide, the perovskite-type composite oxide is produced by formulating materials in accordance with each atomic ratio of a perovskite-type composite oxide represented by the following general formula (1): AxB(1-y)PdyO3+δ (1) wherein A represents at least one element selected from rare earth elements and alkaline earth metals; B represents at least one element selected from transition elements (excluding rare earth elements, and Pd), Al and Si; x represents an atomic ratio satisfying the following condition: 1