Method for increasing internal combustion engine exhaust gas catalyst durability
OwnerMark Crocker, Gregory Thomas Garr +1inventors
InventorsMark Crocker, Gregory Thomas Garr, Thierry Leprince
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Abstract
Durability of emissions catalysts in vehicular and other emissions control systems is significantly increased by positioning, prior to the catalyst-laden catalytic converter, at least one poison trap consisting of a low back pressure structure having a coating which reacts with non-metal or amphoteric oxides to form non-volatile reaction products.
Claims19
A method of increasing the durability of an emissions control exhaust catalyst, said method comprising:
- positioning a low back pressure flow through element between the exhaust valve or port of an internal combustion engine and a catalytic converter element, said pass through element having deposited thereon a catalyst durability enhancing coating comprising a metal oxide, metal compound, a precursor thereof, said metal oxide or metal compound reactive with acidic gases contained in an exhaust stream emanating from said internal combustion engine such that he durability of catalytic elements downstream from said pass through element is enhanced.
An emissions control exhaust system for an internal combustion engine in which hot exhaust gases exit said engine from an exhaust valve or port, said exhaust system comprising
- a) at least one catalytic converter containing an exhaust catalyst which lowers at least one of CO, NOx, particulate matter or HC;
- b) positioned in the exhaust stream of said engine prior to said exhaust catalyst, a discrete low back pressure flow through element having a catalyst durability enhancing coating thereon,
- said durability enhancing coating capable of removing at least a portion of acidic oxides contained in said exhaust stream.
An emissions control exhaust system for an internal combustion engine in which hot exhaust gases exit said engine from an exhaust valve or port, said exhaust system comprising
- a) at least one catalytic converter containing an exhaust catalyst which lowers at least one of CO, NOx, particulate matter, or HC;
- b) positioned in the exhaust stream of said engine prior to said exhaust catalyst, a low back pressure flow through element having a catalyst durability enhancing coating thereon, said element comprising an essentially exhaust emissions catalyst-free portion of a monolith, said monolith having an exhaust emissions catalyst located on a rear-most portion thereof,
- said durability enhancing coating capable of removing at least a portion of acidic oxides contained in said exhaust stream.
Dependencies are inferred from the claim text.