Zeolite having improved heat resistance and catalyst composite using same

Abstract

The present invention relates to a reformed zeolite and a catalyst composite using same which have improved heat resistance and are used in a selective catalytic reduction (SCR) using ammonia or ureaas a reduction agent, or in a filter-type selective catalytic reduction (SDPF) in which a filter is coated with the selective catalytic reduction (SCR), or in a lean nitrogen oxide diesel oxidation catalyst (NA-DOC). Remarkably, alumina components, which are a zeolite coating material, improve heat resistance of the zeolite and, thereby, promote catalytic efficiency at a high temperature.

Description

technical field

[0001] The present invention relates to a reformed zeolite and a catalyst compound using the reformed zeolite, which have improved heat resistance and are used in the selection of ammonia or urea as a reducing agent In active catalytic reduction (SCR) catalysts, or in filter SCR catalysts where the filter is coated with an SCR catalyst, or in lean NOx diesel oxidation catalysts. The reformed zeolites according to the invention are prepared by coating the zeolite with an alumina sol or mixing the two. The reduction of nitrogen oxides (NO x ) and can improve its thermal durability even when exposed to high-temperature exhaust gas discharged from an internal combustion engine or the like. Background technique

[0002] Removal of nitrogen oxides (NO x ) is particularly difficult.

[0003] Selective catalytic reduction (SCR) using ammonia is a stationary source applied to lean conditions to reduce NO x reliable technology. In this technique, NO x Reacts on ...

Examples

Embodiment Construction

[0021] The invention relates to a reformed zeolite coated with alumina sol, a catalyst product with the reformed zeolite placed on a carrier, and an exhaust gas treatment system comprising the catalyst product.

[0022] Zeolite is a crystalline aluminum silicate material that typically has uniform pore sizes of about 3 to 10 Angstroms in diameter, depending on the type of zeolite and the type and number of cations contained in the zeolite lattice. It is a pore size crystalline aluminosilicate aqueous coatings. Those skilled in the art are familiar with the use of zeolites, synthetic zeolites as well as natural zeolites, to facilitate specific reactions, including the selective reduction of nitrogen oxides with ammonia gas as the reducing agent. The object of the present invention is to improve the heat resistance of zeolites by reforming the zeolites, especially by using alumina sols for the preparation of the reformed zeolites. As used herein, the term "alumina sol" is used ...

technical field

[0001] The present invention relates to a reformed zeolite and a catalyst compound using the reformed zeolite, which have improved heat resistance and are used in the selection of ammonia or urea as a reducing agent In active catalytic reduction (SCR) catalysts, or in filter SCR catalysts where the filter is coated with an SCR catalyst, or in lean NOx diesel oxidation catalysts. The reformed zeolites according to the invention are prepared by coating the zeolite with an alumina sol or mixing the two. The reduction of nitrogen oxides (NO x ) and can improve its thermal durability even when exposed to high-temperature exhaust gas discharged from an internal combustion engine or the like. Background technique

[0002] Removal of nitrogen oxides (NO x ) is particularly difficult.

[0003] Selective catalytic reduction (SCR) using ammonia is a stationary source applied to lean conditions to reduce NO x reliable technology. In this technique, NO x Reacts on ...

Examples

Embodiment Construction

[0021] The invention relates to a reformed zeolite coated with alumina sol, a catalyst product with the reformed zeolite placed on a carrier, and an exhaust gas treatment system comprising the catalyst product.

[0022] Zeolite is a crystalline aluminum silicate material that typically has uniform pore sizes of about 3 to 10 Angstroms in diameter, depending on the type of zeolite and the type and number of cations contained in the zeolite lattice. It is a pore size crystalline aluminosilicate aqueous coatings. Those skilled in the art are familiar with the use of zeolites, synthetic zeolites as well as natural zeolites, to facilitate specific reactions, including the selective reduction of nitrogen oxides with ammonia gas as the reducing agent. The object of the present invention is to improve the heat resistance of zeolites by reforming the zeolites, especially by using alumina sols for the preparation of the reformed zeolites. As used herein, the term "alumina sol" is used ...

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