摘要:
An exhaust gas purification catalyst includes a catalyst layer formed on a support. The catalyst layer contains Ce-containing oxide particles having an oxygen storage/release capacity and a catalytic metal. The catalyst layer further contains a large number of iron oxide particles of 300 nm diameter or less that are dispersed therein and are in contact with the Ce-containing oxide particles. When observed by electron microscopy, the proportion of the area of iron oxide particles of 300 nm diameter or less to the total area of all of iron oxide particles in the catalyst layer is 30% or more.
摘要:
In an exhaust gas purification catalyst, particles of a catalytic metal-doped, Ce—Zr-based second mixed oxide are carried on the surfaces of particlcs of a Cc-Zr-based first mixed oxide. The second mixed oxide contains Ce and Zr as metals forming its constituents. Catalytic metal atoms are placed at least one of at and between crystal lattice points of the second mixed oxide. The first mixed oxide contains Ce and Zr as metals forming its constituents but no catalytic metal. Thus, the concentration of catalytic metal on the surfaces of catalyst particles is increased.
摘要:
A catalytic base material for an exhaust gas purifying catalyst is produced by impregnating ceria powders with a barium contained solution and heating the ceria particles at approximately 400 to 1100° C. to create and accumulate barium oxides fixed to surfaces of the ceria particles.
摘要:
The active temperature of an exhaust gas cleaning catalyst is shifted to a higher temperature side when Al.sub.2 O.sub.3 and/or CeO.sub.2 is used as a co-catalyst and/or when an oxidation number of Pt or Ir which is used as the noble active component is plus four.
摘要翻译:当使用Al 2 O 3和/或CeO 2作为助催化剂时和/或当用作贵金属活性组分的Pt或Ir的氧化数为正时,排气净化催化剂的活性温度转移到较高温度侧 四。
摘要:
Disclosed is an exhaust gas purifying catalyst, which comprises a catalyst layer formed on a honeycomb-shaped support. The catalyst layer is formed by mixing a catalyst powder (A) consisting of a composite oxide (RhZrCeNdO) which contains at least Ce, Zr, and a catalytic noble metal composition, and a catalyst powder (B) consisting of a Zr-based oxide (RhZrXO) which contains at least Zr and has Rh existing on a surface thereof. A ratio (RhZrXO/RhZrCeNdO) of a mass of the catalyst powder (B) to a total mass of the catalyst powder (A) and the catalyst powder (B) may be set in the range of 1 to 50%. Further, the catalyst powder (B) may consist of a composite oxide which contains Zr as a primary component, a rare-earth metal except Ce, and Rh. The exhaust gas purifying catalyst of the present invention can provide enhanced exhaust gas conversion efficiency.
摘要:
Disclosed is an exhaust gas purifying catalyst, which comprises a CeZr-based composite oxide capable of maintaining a hollow structure to ensure an oxygen absorbing/releasing capability, even after being exposed to high-temperature exhaust gas. The exhaust gas purifying catalyst comprises a honeycomb-shaped substrate, and a catalyst layer formed on a surface of the substrate. The catalyst layer contains a composite oxide which includes cerium (Ce) and zirconium (Zr) and has a hollow structure, and a catalytic metal supported by the composite oxide. The composite oxide having the hollow structure includes, in a state after being subjected to a thermal aging in Air at 1000° C. for 24 hours, a particle with a shape having an outer diameter of 750 to 1000 nm and a shell thickness of 80 to 120 nm.
摘要:
In an exhaust gas purification catalyst that contains an oxygen storage component containing Ce and Zr, alumina and a catalytic metal, a plurality of primary particles of the oxygen storage component and a plurality of primary particles of the alumina agglomerate to form each of mixed oxide particles and the catalytic metal includes Pd doped in the oxygen storage component particles to constitute each of the oxygen storage component particles with Ce and Zr and exposed at the surfaces of the oxygen storage component particles and Pd adhered to the surfaces of the oxygen storage component particles and the surfaces of the alumina particles.
摘要:
An exhaust gas purification catalyst comprises an oxygen storage component constituted by a mixed oxide containing cerium and zirconium, and a catalytic metal and a NOx storage component are carried on the oxygen storage component. The oxygen storage component is in the form of porous secondary particles in each of which primary particles of an average particle size of less than 10 nm cohere to form fine pores inside each said secondary particle.
摘要:
The present invention relates to an exhaust gas purification catalytic material containing: (a) a mixed oxide containing Ce and Zr for storing and releasing oxygen; and (b) a precious metal catalyst made of one or more kinds of precious metals. The precious metal catalyst comprises a first precious metal catalyst component placed between atoms, at crystal lattice points and/or at oxygen defect sites of the mixed oxide and a second precious metal catalyst component loaded on the surface of the mixed oxide, thereby improving the thermal resistance, oxygen storage capacity and exhaust gas conversion performance of the catalytic material.
摘要:
An exhaust gas emission control catalyst includes an under catalyst layer containing at least one of barium and lanthanum and an over catalyst layer containing an agent for absorbing water in a gas, at least one of the under catalyst layer and over catalyst layer containing catalytic metal.