Title:
CATALYST FOR PURIFYING EXHAUST GAS, ITS PRODUCTION AND PRODUCTION OF HONEYCOMB CATALYST FOR PURIFYING EXHAUST GAS
Document Type and Number:
Japanese Patent JP3517973
Kind Code:
B2
Abstract:
PURPOSE: To decompose NOx in an exhaust under the presence of a reductant such as hydrocarbons even in an oxygen-excess atmosphere by adding Al2O3 or CeO2 as a cocatalyst to a catalyst in which noble metallic active species are deposited on the metal-containing silicate to shift NOx eliminating active temp. of the catalyst to a high temp. side.
CONSTITUTION: Al2O3 or CeO2 as the cocatalyst is added to the catalyst in which the noble metallic active species are deposited on the metal-containing silicate, for example, aluminosilicate (zeolite). Pt, Rh, Ir and Pd which are considered generally to have a low temp. activity are suitable as noble metals, and Pt is suitable especially in the view point of the low temp. activity of the catalyst, and these noble metals may be used in combination. A case in which both Al2O3 and CeO2 are added, and wt. ratio of Al2O3/CeO2 is 0.1-10 is exemplified as a suitable example of the cocatalyst. In this way, an active temp. can be shifted to a high temp. side, moreover, improvement of the heat resistance without substantially decreasing the max. NOx purifying efficiency is advantageous.
Inventors:
Takemoto, Takashi
Kyogoku, Makoto
Koda, Yuki
Takami, Akihide
Ichikawa, Tomoji
Iwakuni, Hideji
Shigetsu, Masahiko
Komatsu, Kazuya
Kyogoku, Makoto
Koda, Yuki
Takami, Akihide
Ichikawa, Tomoji
Iwakuni, Hideji
Shigetsu, Masahiko
Komatsu, Kazuya
Application Number:
JP20847694A
Publication Date:
April 12, 2004
Filing Date:
September 01, 1994
Export Citation:
Assignee:
MAZDA MOTOR CORP
International Classes:
B01D53/94; B01J29/06; B01D53/86; B01J29/068; B01J37/04; (IPC1-7): B01J29/06; B01D53/94
Attorney, Agent or Firm:
前田 弘 （外２名）