0905354-A2 is referenced by 10 patents and cites 6 patents.

An exhaust gas purifying system and a catalyst (14,31) used for the system prevents NOx absorbent from being poisoned by a sulphur compound to keep NOx absorption performance. The catalyst has at least an inner (26) and an outer layer (28,29) on a support material (25), the inner layer having NOx absorbent capable of absorbing NOx and a sulphur compound in the exhaust gas produced from combustion of a lean fuel mixture, releasing the NOx into the exhaust gas and substantially stopping absorbing the sulphur compound when a rich mixture is burnt, and the outer layer having a sulphur compound absorbent capable of absorbing the sulphur compound in the exhaust gas produced from combustion of a lean fuel mixture and capable of discharging the sulphur compound into the exhaust gas when a rich fuel mixture is burnt while the engine operates in a lean-burn zone.; NOx is absorbed by the NOx absorbent in the inner layer and the sulphur compound is absorbed in the sulphur compound absorbent in the outer layer. Therefore the NOx absorbent in the inner layer is protected from being poisoned by the sulphur compound.

Title
Exhaust gas purifying catalyst and system and method of producing the catalyst
Application Number
EP19980307820 19980925
Publication Number
0905354 (A2)
Application Date
September 25, 1998
Publication Date
March 31, 1999
Inventor
Takami Akihide
JP
Okamoto Kenji
JP
Yamada Hiroshi
JP
Iwakuni Hideharu
JP
Kyogoku Makoto
JP
Koda Yuki
JP
Sumida Hirosuke
JP
Assignee
Mazda Motor
JP
IPC
F01N 03/08
F02D 41/02
F01N 03/28
F01N 03/20
F01N 03/10
F01N 03/08
B01D 53/94
B01D 53/86
F02D 41/02
F01N 03/28
F01N 03/20
F01N 03/10
F01N 03/08
B01D 53/94
B01D 53/86
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