The present disclosure is directed to a Low Temperature NOx-Absorber (LT-NA) catalyst composition which exhibits NOx adsorption in a broad temperature and space velocity range, and shifts NOx desorption to a desired temperature range. In particular, the LT-NA composition includes a large pore zeolite containing a palladium component and a small or medium pore zeolite containing a palladium component. Further provided is a catalyst article including the LT-NA catalyst composition, an emission treatment system for treating an exhaust gas including the catalyst article, and methods for reducing a NOx level in an exhaust gas stream using the catalyst article.

Provided is a catalyst article for simultaneously remediating the nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons present in diesel engine exhaust streams. The catalyst article has a soot filter coated with a material effective in the Selective Catalytic Reduction (SCR) of NOx by a reductant, e.g., ammonia.

Provided is a catalyst article for simultaneously remediating the nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons present in diesel engine exhaust streams. The catalyst article has a soot filter coated with a material effective in the Selective Catalytic Reduction (SCR) of NOx by a reductant, e.g., ammonia.

A co-catalyst system for the removal of NO.sub.x from an exhaust gas stream has a layered oxide and a spinel of formula Ni.sub.0.15Co.sub.0.85CoAlO.sub.4. The system converts to nitric oxide to nitrogen gas with high product specificity. The layered oxide is configured to convert NO.sub.x in the exhaust gas stream to an N.sub.2O intermediate, and the spinel is configured to convert the N.sub.2O intermediate to N.sub.2.

This exhaust gas purification catalyst device includes an upper layer which includes first carrier particles and rhodium, and a lower layer which includes second carrier particles, and the upper layer includes a rhodium enriched area in the range a, from the downstream end in the exhaust gas flow to greater than 50% and up to 80% of the upper layer length, and a range b from the upper layer top surface less than 20 m in the depth direction. The rhodium enriched area contains at least 50% and less than 100% of all the rhodium in the upper layer.

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 a process for the treatment of a gas stream containing nitrogen oxides comprising the steps of: (1) providing a gas stream containing one or more nitrogen oxides; (2) contacting the gas stream provided in step (1) with a transition metal containing zeolitic material having a BEA-type framework structure for reacting one or more of the nitrogen oxides; wherein the zeolitic material is obtainable from an organotemplate-free synthetic process, as well as to an apparatus for the treatment of a gas stream comprising containing nitrogen oxides.

Provided are a novel form of AFX zeolite, a novel synthesis technique for producing pure phase small pore zeolites, a novel synthesis method for producing a zeolite with an increased Al pair content, a catalyst comprising the AFX zeolite in combination with a metal, and methods of using the same.

The invention discloses a visible light responsive tricobalt tetraoxide dodecahedron/carbon nitride nanosheet composite and an application thereof in exhaust gas treatment. The preparation method of the composite comprises the following steps: with urea as a precursor, carrying out twice calcination to obtain carbon nitride nanosheet; dispersing the carbon nitride nanosheet into methanol, sequentially adding cobalt nitrate hexahydrate and 2-methylimidazole, and carrying out a reaction to obtain a carbon nitride nanosheet composite; and calcining the carbon nitride nanosheet composite in an air atmosphere at a low temperature to obtain the tricobalt tetraoxide dodecahedron/carbon nitride nanosheet composite. The in-situ growth synthesis method can ensure that the tricobalt tetraoxide obtained by follow-up calcination is uniformly coated on the carbon nitride nanosheet to improve the catalytic performance; the low temperature calcination ensures that the carbon nitride can maintain its wrinkle state and chemical structure during the calcination process.

A denitration catalyst for removing nitrogen oxide in an exhaust gas is represented by the following chemical formula: Ba.sub.3Y.sub.(4-x)A.sub.xO.sub.9, wherein A is an element selected from the group consisting of Bi, Sn, Ga, Mn, Ti, and Al; and X is 0.4 or more and 2 or less. A denitration device has the denitration catalyst for removing nitrogen oxide in an exhaust gas discharged from an exhaust gas generation source including a gas engine, a gas turbine, a melting furnace, or a boiler.