摘要:
A catalytic convertor for treating exhaust gas includes a first catalyst layer formed on a base material and a second catalyst layer formed on the first catalyst layer. The first catalyst layer is composed of metal-containing silicate provided with transition metal by ion exchange and at least one precious metal borne on the silicate, and the second catalyst layer is composed of metal-containing silicate provided with transition metal by ion exchange and at least one metal borne on the silicate which is selected from the group consisting of Zr, Co, Cu, Cr, Mn, Y, Fe, Ni, V, Ti, Zn, Ga, Ba, Mg, La, Ce, Pr, Nd, Sm and Tb and differs from the transition metal provided on the silicate by ion exchange.
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:
In the manufacturing process of the exhaust gas purifying catalyst (3), rhodium is supported by the base material using the rhodium carbonyl cluster solution in which rhodium carbonyl cluster is dissolved into methanol in the step of forming the upper catalytic layer (6) including rhodium and platinum as catalytic metals. By this, the dispersibility of rhodium in the base material is highly raised, and further rhodium is effectively restrained from being oxidized during the manufacturing process of the catalyst (3). Thus, according to the exhaust gas purifying catalyst (3) particularly, the purifying performance of NOx at both of lower exhaust gas temperature and higher exhaust gas temperature is highly improved.
摘要:
An exhaust gas purifying catalyst is produced by, after contacting a ceria powder with a palladium solution and burning the ceria powder to support the palladium on the ceria powder, forming a coating layer of the ceria powder on a catalyst support and impregnating the coating layer with a solution of cerium and burning it to provide palladium oxide particles fixed around ceria particles and a ceria coating so as to cover the palladium particles.
摘要:
In the exhaust gas purifying catalyst (3), palladium is contained as a catalytic component and cerium oxide and (Ce, Pr) compound oxide is contained as a promoter. Now, the weight ratio of cerium oxide to (Ce, Pr) compound oxide is set between 9/1 and 7/3, and the ratio of praseodymium to cerium in the (Ce, Pr) compound oxide is set between 3 mol % and 50 mol %. In this way, because in this exhaust gas purifying catalyst (3), palladium with high low-temperature activity is used for a catalytic component, the exhaust gas purifying performance at low temperature is improved. And because cerium oxide and (Ce, Pr) compound oxide improves catalytic activity of palladium at high temperature, the exhaust gas purifying performance at high temperature, in particular, NOx purifying performance, is improved.
摘要:
A catalyst for cleaning an exhaust gas includes a metal containing silicate containing Al and a metal M constituting a crystalline structure which is selected from a group consisting of Ga, In, B, Mn, Bi, Sc Y, V and Ta, a transition metal or a precious metal being carried in said metal containing silicate. The catalytic active range can be expanded.
摘要:
Catalytic converter for exhaust gas purification comprises a carrier, an oxide layer positioned above the carrier and comprising a compound oxide of cerium (Ce) and magnesium (Mg) with its molar ratio of Mg/(Ce+Mg), and a catalytic metal loaded on the oxide layer. By comprising the compound oxide of cerium and magnesium in the oxide layer, higher purification performance or lower light-off temperature can be obtained under the lean exhaust gas condition during the engine startup.
摘要:
A catalyst comprises an HC trapping material that is capable of trapping HC in an exhaust gas under low temperatures and releasing HC with a raise in temperature and catalytic material containing a Ce—Pr double oxide capable of oxidizing and purifying HC from the HC trapping material with a high efficiency.
摘要:
An inside layer including zeolite and an outside layer including alumina and Pd are formed in a layered shape on a carrier, and Ag and Bi are simultaneously allowed to be carried on the inside and outside layers through impregnation. Thus, production of an alloy through a reaction between Pd and Ag can be suppressed by Bi.
摘要:
In an exhaust gas purification catalyst in which a catalytic coating containing plural kinds of aluminas and plural kinds of oxygen storage components each carrying a catalytic precious metal is coated on a honeycomb support, the catalytic coating is formed of an upper layer and a lower layer, palladium is carried on a first alumina and a Ce—Zr—La—Y-alumina compound having oxygen storage capacity in the lower layer, platinum is carried on a second alumina in the upper layer, and rhodium is carried on a third alumina and a Ce—Zr—Nd mixed oxide having oxygen storage capacity in the upper layer.