摘要:
An exhaust gas purification catalyst is provided with a catalyst coating layer (40) formed on the surface of a substrate (32). This catalyst coating layer (40) is formed of an upper catalyst coating layer (36) in which Rh particles are supported on a porous support, and a lower catalyst coating layer (34) in which Pd particles are supported on a support that contains an ACZ composite oxide made of alumina (Al 2 O 3 ), ceria (CeO 2 ), and zirconia (ZrO 2 ).
摘要:
Provided are exhaust systems and components suitable for use in conjunction with gasoline engines to treat gaseous emissions such as hydrocarbons, nitrogen oxides, and carbon monoxides. Layered three-way conversion (TWC) catalysts comprise an outer layer whose rhodium is supported by an oxygen storage component, such as a ceria-zirconia composite, and the outer layer is substantially free from alumina as a support. The rhodium-containing layer can be free of all other precious metals, such as platinum and palladium. A lower palladium layer is provided where the palladium is supported by a refractory metal oxide. The lower palladium layer can be free of rhodium and platinum and can contain an oxygen storage component that is the same or different from that in the rhodium-containing layer. Methods of making and using these catalysts are also provided,
摘要:
The invention pertains to a catalysed particulate filter provided in its entire dispersion side and within its partition walls with a first catalyst being active in selective catalytic reduction of nitrogen oxides, and in its entire permeate side with a second catalyst combination with a catalyst being active in oxidation of ammonia mixed with a catalyst being active in oxidation of carbon monoxide and hydrocarbons and a method for its preparation. The mean particle size of the first catalyst is smaller than the mean pore diameter of the longitudinal porous walls, and the mean particle size of the second catalyst combination is larger than the mean pore diameter of the longitudinal walls. In the example, the first catalyst is a silica aluminium phosphate SAPO-34 promoted with 2% copper and the second catalyst is a mixture of platinum and palladium (molar ratio 3:1) supported on alumina particles and beta zeolite powder with 1.0% copper.
摘要:
The present invention relates to a nitrogen oxide storage catalyst comprising: a substrate; a first washcoat layer provided on the subtstrate, the first washcoat layer comprising a nitrogen oxide storage material, a second washcoat layer provided on the first washcoat layer, the second washcoat layer comprising a hydrocarbon trap material, wherein the hydrocarbon trap material comprises substantially no element or com- pound in a state in which it is capable of catalyzing selective catalytic reduction, preferably wherein the hydrocarbon trap material comprises substantially no element or compound in a state in which it is capable of catalyzing a reaction wherein nitrogen oxide is reduced to N 2 , said catalyst further comprising a nitrogen oxide conversion material which is either comprised in the second washcoat layer and/or in a washcoat layer provided between the first washcoat layer and the second washcoat layer.
摘要:
La composition de l'invention est à base d'oxyde de zirconium, d'oxyde de cérium et d'oxyde d'yttrium ou elle est à base d'oxyde de zirconium, d'oxyde de cérium et d'au moins deux oxydes de deux terres rares autres que le cérium, dans une proportion en masse en oxyde de zirconium d'au moins 20% et en oxyde de cérium d'au plus 70%, et elle est caractérisée en ce qu'elle présente après calcination à une température de 900°C pendant 4 heures, deux populations de pores dont les diamètres respectifs sont centrés, pour la première, autour d'une valeur comprise entre 20 et 40 nm et, pour la seconde, autour d'une valeur comprise entre 80 nm et 200 nm. La composition peut être utilisée pour le traitement des gaz d'échappement des moteurs à combustion interne.
摘要:
Die vorliegende Erfindung betrifft die Verwendung von Mischoxiden aus Ceroxid, Zirkonoxid, Seltenerdsesquioxid und Nioboxid als katalytisch aktives Material zur selektiven katalytischen Reduktion von Stickoxiden mit Ammoniak oder einer zu Ammoniak zersetzlichen Verbindung im Abgas von überwiegend mager betriebenen Verbrennungsmotoren in Kraftfahrzeugen, sowie Zusammensetzungen bzw. Katalysatoren, die diese Mischoxide in Kombination mit Zeolithverbindungen und/oder zeolithähnlichen Verbindungen enthalten und die sich zur Entstickung von mageren Kraftfahrzeugabgasen in allen wesentlichen Betriebszuständen eignen.
摘要:
A vanadia-based catalytic composition for reduction of nitrogen oxides includes a titania-based support material; vanadia deposited on the titania-based support material; a primary promoter comprising tungsten oxide, molybdenum oxide or combinations thereof; and an amount of phosphate to achieve a mole ratio of phosphorus to vanadium plus molybdenum of about 0.2:1 or greater. A zirconia, tin or manganese oxide can be added to further inhibit the volatility of molybdenum. Results show low SO 2 oxidation rates and excellent NO x conversion and/or molybdenum stability.
摘要:
L'invention concerne un dispositif de traitement des gaz d'échappement issus d'un moteur thermique, comportant un filtre à particules constitué d'un matériau poreux pour piéger et oxyder les suies et un catalyseur de réduction sélective des oxydes d'azote déposé sur les faces de sortie des parois du filtre à particules. L'invention consiste en ce que ledit catalyseur de réduction sélective est choisi parmi ceux du type présentant une surface spécifique d'au moins 65M2/g après vieillissement à 800 °C.