High-performance zeolite for reducing nitrogen oxide emissions, method of preparing same and catalyst using same
AssigneesHyundai Motor Company, Kia Motors Corporation, Heesuna Catalysts Corporation
InventorsPyung Soon Kim, Young Jin Kim, Chang Hwan Kim, Seung Chui Na, Seung Ho Oh, Young San Yoo, Ho Dong Kim
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Abstract
Disclosed is a method of preparing a high-performance zeolite catalyst for reducing nitrogen oxide emissions, and more particularly a technique for preparing a zeolite catalyst, suitable for use in effectively removing nitrogen oxide (NOx), among exhaust gases emitted from vehicle internal combustion engines through selective catalytic reduction (SCR), thereby exhibiting high efficiency, high chemical stability and high thermal durability upon SCR using the prepared catalyst.
Claims4
A copper-impregnated LTA zeolite catalyst for selective catalytic reduction of nitrogen oxide, the catalyst comprising
- a high-silica-content LTA zeolite in which copper is ion-exchanged,
- wherein a silicon/aluminum (Si/Al) molar ratio is 8 to 30 and a particle size is 0.5 to 5.0 μm,
- wherein the copper-impregnated LTA zeolite has a crystallinity of 50% or more after a hydrothermal treatment at 900° C. for 1 to 25 hours and a crystallinity of 30% or more after a base treatment, and
- wherein in the base treatment, the catalyst is placed in an aqueous ammonia solution adjusted to a pH of 9.0 to 9.5, left to be heated at 50 to 70° C. for 100 to 200 hours, and then filtered and dried.
Dependencies are inferred from the claim text.