An exhaust gas purification system for lowering the content of impurities in a lean exhaust gas of an internal combustion engine comprising, a feeding device that feeds ammonia or a compound decomposable to ammonia into an exhaust gas stream containing nitrogen oxides; a selective catalytic reduction catalyst comprising vanadium (V-SCR catalyst) which catalyzes the nitrogen oxides with ammonia in a temperature range of about 150° C. to about 400° C. and at an NO.sub.2/NO.sub.x ratio of about 0.3 to about 0.9; and a downstream system comprising a diesel oxidation catalyst.

A composition for exhaust gas purification including first alumina including alumina containing lanthanum and second alumina including alumina containing lanthanum. The first alumina has a higher lanthanum content than the second alumina. The second alumina has a larger particle size than the first alumina. The lanthanum content of the first alumina is preferably 2 to 12 mass %, in terms of oxide, based on the total mass of alumina and lanthanum oxide of the first alumina. The lanthanum content of the second alumina is preferably 9 mass % or less, in terms of oxide, based on the total mass of alumina and lanthanum oxide of the second alumina.

The present invention relates to the use of different regeneration strategies for nitrogen oxide storage catalysts (NOx storage catalyst, LNT or NSC), depending on the exhaust gas temperatures, to reduce in the total exhaust gas the greenhouse gas N.sub.2O (nitrous oxide) that is produced as a secondary emission during the regeneration of the storage catalyst. If the exhaust gas temperature is below 275° C.-290° C., regeneration takes place using a strategy with short pulses of around 2 seconds and λ Lambda 0.95 rich.

Reductant delivery systems are disclosed that include a dry reductant source and a liquid reductant source which are operable to selectively provide gaseous reductant and liquid reductant to an exhaust aftertreatment system for treatment and reduction of NOx emissions. The gaseous reductant is provided to the exhaust aftertreatment system for treatment of NOx emissions under a first temperature condition associated with the exhaust system and the liquid reductant for treatment of NOx emissions under a second temperature condition associated with the exhaust system.

Provided is a catalyst having better denitration efficiency at low temperatures compared to the prior art, during a selective catalytic reduction reaction in which ammonia is used as a reducing agent. This denitration catalyst contains vanadium oxide including vanadium pentoxide and has a defect site in which oxygen deficiency occurs in a crystal structure of the vanadium pentoxide.

A NOx adsorber catalyst for treating an exhaust gas from a diesel engine. The NOx adsorber catalyst comprises a first region comprising a NOx adsorber material comprising a first molecular sieve catalyst. The first molecular sieve catalyst comprises a first noble metal and a first molecular sieve, and the first molecular sieve contains the noble metal. The first molecular sieve has an STI Framework Type.

The present invention relates to a method for producing automobile exhaust gas catalytic converters, to the catalytic converters as such and to the use thereof. In particular, the method comprises a step which results in a smaller particle size of the catalytically active material used.

The present invention is directed to a method of preparing a synthetic crystalline material, designated as JMZ-12, with a framework built up by the disorder AEI and CHA structures, substantially free of framework phosphorous and prepared preferably in the absence of halides such as fluoride ions. Such method comprises the step of heating a reaction mixture under crystallization conditions for a sufficient period to form a disordered zeolite having both CHA and AEI topologies, wherein the reaction mixture comprises at least one source of aluminum, at least one source of silicon, a source of alkaline or alkaline-earth cations, and a structure directing agent containing at least one source of quaternary ammonium cations and at least one source of alkyl-substituted piperidinium cations in a molar ratio of 0.20 to about 1.4. The resulting zeolites are useful as catalysts, particularly when used in combination with exchanged transition metal(s) and, optionally, rare earth metal(s).

This invention belongs to the technical field of green preparation of environmentally friendly catalysts, and discloses a preparation method and application of mesoporous FeCu—ZSM-5 molecular sieve, in particular to a method for synthesizing mesoporous FeCu—ZSM-5 molecular sieve by one-pot method and the application in selective catalytic reduction (SCR) denitration reaction. This invention firstly proposes to combine the two calcinations after demolding and ion exchange into one, that is, the original powder is directly calcined to prepare a FeCu—ZSM-5 molecular sieve. The molecular sieve has several advantages such as window with wide temperature window, low cost, good hydrothermal stability and high SCR denitrification activity. Besides, the synthesis process does not use a (large) pore template, nor does it use a post-treatment method to construct the mesopores. Therefore, the method of the invention not only has the advantages of simple process, simple operation, but also good economic and environmental benefits.

An aftertreatment system includes an inlet exhaust section, an outlet exhaust section, a first aftertreatment component, a first dosing module, and a second dosing module. The inlet exhaust section receives exhaust. The outlet exhaust section is in fluid communication with the inlet exhaust section. The first aftertreatment component receives the exhaust from the inlet exhaust section, treats the exhaust, and provides the exhaust to the outlet exhaust section. The first dosing module is positioned along the inlet exhaust section. The first dosing module is structured to selectively dose the exhaust with reductant. The second dosing module is positioned along the outlet exhaust section. The second dosing module is structured to selectively dose the exhaust with the reductant.