发明名称 |
Composite catalyst, used for reducing nitrogen oxides in I.C. engine exhaust gases, comprises redox-active cerium oxide species on outer surface of carrier, and indium-oxo species in carrier pores |
摘要 |
Composite catalyst comprises redox-active CeOx species on the outer surface of a crystalline porous aluminum silicate as carrier, and an indium-oxo species on the inner surface, i.e. in the pores, of the carrier, and being Lewis acid active as well as redox-active. An Independent claim is also included for a process for the production of a composite catalyst comprising charging a suspended catalyst carrier in its H<+>- or NH<+>-form by precipitating In(OH)3 from an indium salt solution or by grinding with In2O3 and subsequently charging by precipitating cerium hydroxide from a cerium salt solution; or charging a suspended catalyst carrier in its H<+>- or NH<+>-form by precipitating indium hydroxide and cerium hydroxide from an aqueous indium salt solution and cerium salt solution or by grinding with In2O3 and CeO2; treating with a gaseous reductant at 300-600 deg C for 0.5-6 hours; and treating the reduced precursor with a gaseous oxidant at 300-600 deg C for 0.5-6 hours. Preferred Features: The ratio of the cerium species on the outer surface to the cerium species in the pores is at least 4: 1. The amount of CeOx species present is 4-20 wt.%. The CeOx species can be replaced with La2O3 and/or ZrO2. The crystalline porous aluminum silicate is a MFI zeolite, MOR zeolite and/or BEA zeolite.
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申请公布号 |
DE10065717(A1) |
申请公布日期 |
2002.07.11 |
申请号 |
DE20001065717 |
申请日期 |
2000.12.22 |
申请人 |
INSTITUT FUER ANGEWANDTE CHEMIE BERLIN-ADLERSHOF E.V.;W. C. HERAEUS GMBH & CO. KG;RUHR-UNIVERSITAET BOCHUM |
发明人 |
BERNDT, HEINZ;RICHTER, MANFRED;SCHUETZE, FRANK-WALTER;STROEDER, ULRICH;SIMON, FALK;LIESE, THORSTEN;SAWADE, THOMAS;GRUENERT, WOLFGANG |
分类号 |
B01D53/94;(IPC1-7):B01D53/86;F01N3/08 |
主分类号 |
B01D53/94 |
代理机构 |
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代理人 |
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