Catalyzed diesel exhaust particulate filter
AssigneeEngelhard Corporation
InventorsJoseph C. Dettling, Robert Skomoroski
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Abstract
A self-cleaning diesel exhaust particulate filter is disclosed wherein burn-off of collected particulate matter is accomplished at certain exhaust gas temperatures, the filter being provided with a catalyst mixture consisting essentially of a platinum group metal and an alkaline earth metal oxide. The platinum group metal may be one or both of platinum and rhodium and the alkaline earth metal oxide may be magnesium oxide. The presence of the catalyst mixture serves to lower the temperature at which ignition of the collected particulates is initiated.
Claims21
A catalyzed diesel exhaust particulate filter comprises a high temperature resistant filter element having porous walls and being dimensioned and configured to filter particulates present in diesel engine exhaust gas flowed through the catalyzed filter and collect such particulates on the surfaces of the porous walls, the surfaces of the walls having thereon a catalyst consisting essentially of a mixture of at least one platinum group metal and at least one alkaline earth metal oxide, which catalyst lowers the temperature at which the collected particulates are ignited and combustion thereof is initiated, whereby the particulates are continuously removed from the filter by burning.
A catalyzed diesel exhaust particulate filter comprises a high temperature resistant, ceramic filter element having porous walls and being dimensioned and configured to filter particulates present in diesel engine exhaust gas flowed through the catalyzed filter and collect such particulates on the surfaces of the porous walls, the surfaces of the walls having thereon a catalyst consisting essentially of (i) a platinum group metal selected from the group consisting of one or both of platinum and rhodium, and (ii) at least one alkaline earth metal oxide essentially including magnesium oxide, which catalyst lowers the temperature at which the collected particulates are ignited and combustion thereof is initiated, whereby the particulates are continuously removed from the filter by burning.
A method of removing deposits from the exhaust gas of a diesel engine comprises passing the exhaust gas through a catalyzed diesel exhaust particulate filter comprising a high temperature resistant filter element having porous walls and being dimensioned and configured to filter the particulates present in diesel engine exhaust gas flowed through the catalyzed filter and collect such particulates on the surfaces of the porous walls, the surfaces of the walls having thereon a catalyst consisting essentially of a mixture of at least one platinum group metal and at least one alkaline earth metal oxide, which catalyst lowers the temperature at which the collected particulates are ignited and combustion thereof is initiated, whereby the particulates are continuously removed from the filter by burning.
Dependencies are inferred from the claim text.