摘要:
An oxygen storage material comprising cerium oxide and at least one second oxide of a metal M1 is disclosed as well as a process for manufacturing the material and the use of this material in an exhaust gas cleaning catalyst. In a preferred embodiment the oxygen storage material comprises particles from a Ce/M1 mixed oxide solid solution coated with an oxide of another metal M2. Metal M1 e.g. can be calcium or zirconium while metal M2 most preferably is aluminum.
摘要翻译:公开了一种包含氧化铈和至少一种金属M 1 O 2的第二氧化物的储氧材料,以及用于制造材料的方法以及在废气清洁催化剂中使用该材料。 在优选的实施方案中,储氧材料包含涂覆有另一种金属M 2 O 2的氧化物的Ce / M 1混合氧化物固溶体的颗粒。 金属M 1,例如 可以是钙或锆,而金属M 2最优选是铝。
摘要:
A process for reducing the nitrogen oxides present in a lean exhaust gas from an internal combustion engine by selective catalytic reduction on a reduction catalyst using ammonia, wherein a fraction of the nitrogen monoxide present in the exhaust gas is oxidized to nitrogen dioxide before the exhaust gas, together with ammonia, is passed over the reduction catalyst. The reduction catalyst contains a zeolite exchanged with transition metals and oxidation of the nitrogen monoxide is performed in such a way that the exhaust gas contains 30 to 70 vol. % of nitrogen dioxide before contact with the reduction catalyst.
摘要:
A method of depositing catalytically active components on high-surface carrier materials is disclosed by dispersing the carrier materials in water and mixing this dispersion with an aqueous solution of soluble precursors of the catalytically active components. The pH of the dispersion is adjusted to a value between 6 and 8 before the aqueous solution of the precursors is supplied by capillary injection under constant agitation of the dispersion and thereafter, if necessary, the precursors of the catalytically active components are precipitated on the carrier material by capillary injection of a dilute base.
摘要:
A catalyst for purifying the exhaust gases from diesel engines. The catalyst contains a zeolite mixture of several zeolites with different moduli and platinum group metals as well as further metal oxides from the group aluminum silicate, aluminum oxide and titanium oxide, wherein the aluminum silicate has a ratio by weight of silicon dioxide to aluminum oxide of 0.005 to 1 and the platinum group metals are deposited on only the further metal oxides.
摘要:
This invention relates to a method and a corresponding apparatus for coating open-pored bodies with at least one coating suspension. In particular, the coating suspension has solids and solutes in a liquid medium in a quantity in wet state which is to correspond to at least a required target quantity. The coating operation has a variation in the applied wet coating quantity from one body to the other. The method according to the invention is characterized by the steps of: coating the body with an actual quantity of the coating suspension, which is always larger than the required target quantity taking the variation of the coating operation into account, determining the difference between the actual quantity and the required target quantity, and reducing the difference between actual quantity and target quantity by removing still wet coating suspension.
摘要:
The invention proposes a particulate filter having a catalytic coating which contains two catalysts arranged one behind the other. The first catalyst is located in the gas inlet region of the filter and contains a palladium/platinum catalyst. The second catalyst is arranged downstream of the first catalyst and preferably contains platinum alone as catalytically active component. The combination of these two catalysts provides the coated filter with a good ageing stability and resistance to sulphur poisoning.
摘要:
The invention relates to a catalyst arrangement for purifying the exhaust gases of internal combustion engines operated under lean conditions. It is proposed that a thinwalled, porous carrier be coated on one side with a nitrogen oxide storage catalyst and on the other side with an SCR catalyst. When the exhaust gas is passed through the catalytic coatings and the support material, a significant improvement in the nitrogen oxide conversion is achieved compared to a series arrangement of the catalysts on separate carriers. Wall flow filters have been found to be useful as thin-walled carriers.
摘要:
The invention provides a process for reducing the amounts of carbon monoxide, hydrocarbons and soot particles in the lean exhaust gas from an internal combustion engine using a particle filter, wherein the soot particles have a soot ignition temperature TZ and the particle filter is regenerated from time to time by raising the temperature of the particle filter to above the soot ignition temperature and burning the soot particles, wherein the temperature of the filter is increased to the temperature required to initiate soot ignition by burning additional fuel on the catalytic coating when the exhaust gas back pressure reaches a predetermined value. The process is characterised in that the particle filter is provided with a catalytic coating comprising a first group of components for reducing the ignition temperature of soot, said first group of components contains at least one oxygen storage component and at least one platinum group metal selected from the group consisting of platinum, palladium and rhodium. In a preferred embodiment of the process the catalytic coating further comprises a second group of components for oxidising carbon monoxide and hydrocarbons, said second group of components comprises at least a support material selected from the group consisting of aluminium oxide, silicon oxide, titanium oxide, zirconium oxide and zeolite and at least one platinum group metal selected from the group consisting of platinum, palladium and rhodium deposited on said support materials.
摘要:
The invention relates to a method and an apparatus of operating a drive system comprising an engine and an exhaust gas purification unit containing a catalyst, where the engine emits an exhaust gas having an exhaust gas temperature and the catalyst has a catalytic activity for the purification of the exhaust gas. In the method, an aging-induced decrease in the catalytic activity of the catalyst is compensated at least part of the time by increasing the exhaust gas temperature of the engine.
摘要:
An oxygen storage material comprising cerium oxide and at least one second oxide of a metal M1 is disclosed as well as a process for manufacturing the material and the use of this material in an exhaust gas cleaning catalyst. In a preferred embodiment the oxygen storage material comprises particles from a Ce/M1 mixed oxide solid solution coated with an oxide of another metal M2. Metal M1 e.g. can be calcium or zirconium while metal M2 most preferably is aluminum.
摘要翻译:公开了一种包含氧化铈和至少一种金属M 1 O 2的第二氧化物的储氧材料,以及用于制造材料的方法以及在废气清洁催化剂中使用该材料。 在优选的实施方案中,储氧材料包含涂覆有另一种金属M 2 O 2的氧化物的Ce / M 1混合氧化物固溶体的颗粒。 金属M 1,例如 可以是钙或锆,而金属M 2最优选是铝。