EP0287217A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Catalyst for simultaneous decomposition of oxides of nitrogen and oxidation of carbon monoxide under cycled operating conditions
Assignee: Motors Liquidation Co
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Filing: 1988-03-16
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Granted: —
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Expires: 2008-03-16
Abstract
Abstract This invention discloses an automotive exhaust gas treatment catalyst composed of one or more noble metals dispersed on CeO2-RE2O3 carrier particles, where RE represents a rare earth metal. The ceria-rare earth oxide carrier for the noble metal facilitates the simultaneous oxidation of carbon monoxide, CO, and the decomposition of nitric oxide, NO. The catalyst is particularly useful when the air-fuel mixture to the automobile engine is continually cycled between fuel-rich and fuel-lean ratios compared to the stoichiometric air-fuel ratio.
Inventors
- 👤 Byong Kwon Cho
- 👤 Christopher Joseph Stock
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 17:53
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/08; F01N3/10; B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J; B01J23/00; B01J23/38; B01J23/54; B01J23/56; B01J23/63; B01D2255/00; B01D2255/90; B01D2255/908; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
71 words
A catalyst for treating automotive exhaust gases containing both carbon monoxide (CO) and nitric oxide (NO), the catalyst comprising one or more noble metals deposited on carrier particles containing ceria, characterised in that the carrier particles are formed from a chemically-reacted, solid solution of 80 to 95 mole percent ceria (CeO₂) and 5 to 20 mole percent of a rare earth metal oxide, RE₂O₃, where RE represents a rare earth metal.
Claim 2
Dependent Claim
71 words
A catalyst for treating automotive exhaust gases containing both carbon monoxide (CO) and nitric oxide (NO), the catalyst comprising one or more noble metals deposited on carrier particles containing ceria, characterised in that the carrier particles are formed from a chemically-reacted, solid solution of 80 to 95 mole percent ceria (CeO₂) and 5 to 20 mole percent of a rare earth metal oxide, RE₂O₃, where RE represents a rare earth metal.
Claim 3
Dependent Claim
21 words
A catalyst according to claim 1, in which the noble metal is platinum, rhodium, or a mixture of platinum and rhodium.
Claim 4
Dependent Claim
32 words
A catalyst according to claim 1 or 2, in which the carrier particles comprise a chemically-reacted, solid solution of 85 to 90 mole percent CeO₂ and 10 to 15 mole percent RE₂O₃.
Claim 5
Dependent Claim
17 words
A catalyst according to claim 1, 2 or 3, in which the rare earth metal comprises gadolinium.
Claim 6
Independent Claim
93 words
A method of treating the exhaust gas produced from the operation of a hydrocarbon-fuelled internal combustion engine comprising continually cycling an air-fuel mixture supplied to the engine between a fuel-rich condition and a fuel-lean condition whilst contacting the exhaust gas with a catalyst comprising one or more noble metals deposited on ceramic carrier particles, characterised in that the carrier particles are formed from a solid solution chemical reaction product of a mixture comprising 80 to 95 mole percent CeO₂ and 5 to 20 mole percent RE₂O₃, where RE is a rare earth metal.
Claim 7
Independent Claim
93 words
A method of treating the exhaust gas produced from the operation of a hydrocarbon-fuelled internal combustion engine comprising continually cycling an air-fuel mixture supplied to the engine between a fuel-rich condition and a fuel-lean condition whilst contacting the exhaust gas with a catalyst comprising one or more noble metals deposited on ceramic carrier particles, characterised in that the carrier particles are formed from a solid solution chemical reaction product of a mixture comprising 80 to 95 mole percent CeO₂ and 5 to 20 mole percent RE₂O₃, where RE is a rare earth metal.
Claim 8
Dependent Claim
48 words
A method of treating the exhaust gas produced from the operation of a hydrocarbon-fuelled internal combustion engine according to claim 5, in which the solid solution chemical reaction product is formed from a mixture comprising 85 to 90 mole percent CeO₂ and 10 to 15 mole percent RE₂O₃.
Claim 9
Dependent Claim
32 words
A method of treating the exhaust gas produced from the operation of a hydrocarbon-fuelled internal combustion engine according to claim 5 or 6, in which the rare earth metal RE is gadolinium.
References Cited (Backward Citations)
No citation records indexed.
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