Abstract:
Catalysts that improve carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxides (NOx) light-off performance are provided. A catalyst composite for combustion engines, as provided herein, comprises a carrier and a first layer comprising a catalytic material on the carrier, the catalytic material comprising a palladium component supported on both a ceria-praseodymia-based oxygen storage component and a ceria-zirconia-based oxygen storage component, wherein the first layer is essentially free of alumina. The catalytic material is effective to substantially simultaneously oxidize carbon monoxide and hydrocarbons and reduce nitrogen oxides.
Abstract:
The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H 2 S 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:
A composition of formula (I) Ce 1-a-b-c N a M b D c O x wherein M stands for one or more elements from the group of alkaline metals, except sodium, N is Bi and/or Sb, D is is present, or is not present, and if present is selected from one or more of Mg, Ca, Sr, Ba; Y, La, Pr, Nd, Sm, Gd, Er; Fe, Zr, Nb, Al; a is a number within the range of 0
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:
Steam reforming a hydrocarbon feed such as liquefied petroleum gas is conducted in the presence of a catalyst comprising a precious metal such as rhodium on a support comprising ceria, zirconia and praseodymium oxide.
Abstract:
A composite oxide and a catalyst for purifying exhaust gas using the same are provided, which oxide has excellent heat resistance, including that a large specific surface area is maintained even when the composite oxide is used in a high temperature environment, and that, even after calcination at 800 °C for 2 hours, no AECeO 3 phase is detected and increase in CeO 2 crystallite size is inhibited. The composite oxide contains, in terms of oxides, 60 to 98 mass% of a cerium-containing element, the cerium-containing element consisting of Ce and at least one element selected from rare earth elements other than Ce and including Y, Zr, and Si at 85:15 to 100:0 by mass, 1 to 20 mass% of an alkaline earth metal element, and 1 to 20 mass% aluminum in terms of AI2O 3 , wherein the composite oxide has properties of exhibiting a specific surface area of not smaller than 40 m 2 /g as measured by the BET method after calcination at 800 °C for 2 hours, and having no AECeO 3 phase and having a CeO 2 crystallite size in the (111) plane of not larger than 15 nm, as determined by X-ray diffraction after calcination at 800 °C for 2 hours.
Abstract translation:提供一种复合氧化物和使用其的净化废气的催化剂,该氧化物具有优异的耐热性,即使在复合氧化物在高温环境中使用时也能维持大的比表面积,并且即使在 在800℃下煅烧2小时,不检测到AECeO 3相,并抑制CeO 2微晶尺寸的增加。 复合氧化物以氧化物计含有60〜98质量%的含铈元素,由Ce组成的含铈元素和选自Ce以外的稀土元素中的至少一种元素,包括Y,Zr和 Si:85:15〜100:0,碱土类金属元素为1〜20质量%,Al 2 O 3为1〜20质量%,其中复合氧化物的比表面积为 在800℃下煅烧2小时后,通过BET法测定,并且在(111)面内具有不大于15nm的AECeO 3相和CeO 2微晶尺寸,通过X测定,小于40m 2 / g 在800℃煅烧2小时后的衍射。
Abstract:
The present invention relates to a catalyst comprising a substrate and a catalyst coating, the catalyst coating comprising two or more layers, said layers comprising: (a) a first layer provided on the substrate, said first layer comprising Pd and Rh; and (b) a second layer provided on the first layer, said second layer comprising Pt and/or Pd; the first and second layers each further comprising: one or more particulate support materials; one or more oxygen storage component (OSC) materials; and one or more nitrogen oxide storage materials comprising one or more elements selected from the group of alkali and/or alkaline earth metals, wherein the total amount of alkali and alkaline earth metals comprised in the one or more nitrogen oxide storage materials contained in the catalyst ranges from 0.18 to 2.0 g/in³ calculated as the respective alkali metal oxides M 2 O and alkaline earth metal oxides MO, as well as to a method for the production of a catalyst, and to a process for the treatment of a gas stream, in particular of an exhaust gas stream resulting from an internal combustion engine.
Abstract:
A catalyst for purifying exhaust gases includes a substrate, and a catalytic layer. The catalytic layer includes a lower catalytic layer, a first upper catalytic layer, and a second upper catalytic layer. The lower catalytic layer being loaded with Pd and/or Pt is formed on the substrate. The first upper catalytic layer being loaded with Pd covers an upstream side of the lower catalytic layer, and exhibits a concentration of loaded Pd that falls in a range of from 4.5 to 12% by mass when the entirety of the first upper catalytic layer is taken as 100% by mass. The second upper catalytic layer being loaded with Rh covers a downstream side of the lower catalytic layer.
Abstract:
An exhaust gas purification catalyst includes: a lower catalyst layer that contains a ceria-zirconia mixed oxide having 50 to 70 mass% of CeO2 and 5 mass% or more of Pr2O3 and carries at least one of Pt and Pd; and an upper catalyst layer that contains at least zirconia and carries at least Rh, wherein the total amount of CeO2 per liter of the carrier base is 15 to 30 g. Because the amount of CeO2 is small, formation of H2S is suppressed and a high capability of adsorbing and releasing oxygen is brought out in spite of the small amount of CeO2.