Performance enhancement of a platinum-containing catalyst via exhaust gas hydrogen enrichment
AssigneeBASF Mobile Emissions Catalysts LLC
InventorsShiang Sung, Chunxin Ji, Pavel Ruvinskiy
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Abstract
The disclosure provides a platinum-containing three-way conversion (TWC) catalyst, and a system for treating an exhaust gas stream from a gasoline engine using the TWC catalyst. The system is configured to introduce controlled quantities of hydrogen gas into the exhaust gas stream upstream of the platinum-containing TWC catalyst article during a cold-start period. Further provided are related methods of treating such exhaust streams. Such systems and methods are useful in reducing a level of one or more of hydrocarbons, carbon monoxide, and nitrogen oxide in a gaseous exhaust stream from a gasoline engine.
Claims35
A platinum-containing three-way conversion (TWC) catalyst article effective to oxidize carbon monoxide and hydrocarbons and reduce nitrogen oxides in an exhaust gas stream from a gasoline engine, the platinum-containing TWC catalyst article comprising a substrate, a first catalyst composition disposed on at least a portion of the substrate, and a second catalyst composition disposed on at least a portion of the substrate, wherein the second catalyst composition comprises:
- a first palladium component, wherein at least a portion of the first palladium component is impregnated on a first refractory metal oxide support, and at least another portion of the first palladium component is impregnated on a first oxygen storage component;
- and
- a rhodium component impregnated on a second refractory metal oxide support;
- and
- wherein the first catalyst composition comprises:
- a second palladium component, wherein at least a portion of the second palladium component is impregnated on a third refractory metal oxide support, and at least another portion of the second palladium component is impregnated on a second oxygen storage component;
- and
- a platinum component, wherein the platinum component is impregnated on the third refractory metal oxide support, or wherein the platinum component is impregnated on the second oxygen storage component.
A method of enhancing the cold-start catalytic performance of a platinum-containing TWC catalyst article, wherein the platinum-containing TWC catalyst article comprises a substrate, a first catalyst layer disposed on the substrate, and a second catalyst layer disposed on the first layer, wherein the second catalyst layer comprises a second catalyst composition comprising:
- a first palladium component, wherein at least a portion of the first palladium component is impregnated on a first refractory metal oxide support, and at least another portion of the first palladium component is impregnated on a first oxygen storage component;
- and
- a rhodium component impregnated on a second refractory metal oxide support;
- and
- wherein the first catalyst layer comprises a first catalyst composition comprising:
- a second palladium component, wherein at least a portion of the second palladium component is impregnated on a third refractory metal oxide support, and at least another portion of the second palladium component is impregnated on a second oxygen storage component;
- and
- a platinum component, wherein the platinum component is impregnated on the third refractory metal oxide support, or wherein the platinum component is impregnated on the second oxygen storage component;
- the method comprising:
- contacting the exhaust gas stream with the platinum-containing TWC catalyst article, located downstream of a gasoline engine and in fluid communication with an exhaust gas stream;
- controlling a concentration by volume of H2 in the exhaust gas stream for a period of time, wherein
- controlling the concentration by volume of H2 comprises introducing hydrogen gas (H2) from a H2 source into the exhaust gas stream upstream of the TWC catalyst article;
- and
- modulating the H2 introduction using a signal from a feed-back sensor.
Dependencies are inferred from the claim text.