Title:
ディーゼルエンジンの排気ガスから窒素含有有害ガスを減少させる触媒
Document Type and Number:
Japanese Patent JP2009538724
Kind Code:
A
Abstract:
In exhaust gas purification units for decreasing nitrogen oxides in lean-burn exhaust gas of internal combustion engines by selective catalytic reduction by means of ammonia, introduction of excess ammonia leads to undesirable emissions of unused ammonia. These emissions can be decreased by means of ammonia barrier catalysts. In the ideal case, ammonia is oxidized to nitrogen and water by these catalysts. These require additional space in the exhaust gas purification unit which may have to be taken away from the space provided for the SCR main catalyst. In addition, the use of such ammonia barrier catalysts can result in overoxidation of the ammonia to nitrogen oxides. To overcome these disadvantages, a catalyst containing two superposed layers is proposed for the removal of nitrogen-containing pollutant gases from diesel exhaust gas. The lower layer contains an oxidation catalyst and the upper layer can store at least 20 milliliters of ammonia per gram of catalyst material. This catalyst displays reduced ammonia breakthrough at good SCR conversions in the low-temperature range. It can be used as SCR catalyst having reduced ammonia breakthrough or as ammonia barrier catalyst.
More Like This:
Inventors:
Nicola Seeger
Wolfgang Schneider
Yvonne Demel
Rotor mussman
Ralph Zesselman
Thomas Kreuzer
Wolfgang Schneider
Yvonne Demel
Rotor mussman
Ralph Zesselman
Thomas Kreuzer
Application Number:
JP2009512442A
Publication Date:
November 12, 2009
Filing Date:
May 04, 2007
Export Citation:
Assignee:
Umicore AG & Co.KG
International Classes:
B01J29/76; B01D53/94; F01N3/08; F01N3/10; F01N3/28
Attorney, Agent or Firm:
Toshio Yano
Toshiomi Yamazaki
Takuya Kuno
Hiroshi Sugimoto
Kimihiro Hoshi
Hiroyasu Ninomiya
Einzel Felix-Reinhard
Reinhard Einsel
Toshiomi Yamazaki
Takuya Kuno
Hiroshi Sugimoto
Kimihiro Hoshi
Hiroyasu Ninomiya
Einzel Felix-Reinhard
Reinhard Einsel