Diesel engine exhaust treatment system and method including a platinum group metal trapping device
AssigneeFord Global Technologies, LLC
InventorsHungwen Jen, Giovanni Cavataio, James W. Girard
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Abstract
A diesel engine exhaust treatment system and method is provided which includes a platinum group metal trapping device (16) comprising cerium oxide or a perovskite material positioned between a diesel oxidation catalyst and an SCR catalyst. The platinum group metal trapping device traps trace amounts of platinum group metals which may be released from the diesel oxidation catalyst during engine operation and prevents them from accumulating on the SCR catalyst, preventing potential contamination of the SCR catalyst as well as ensuring that the performance of the SCR catalyst is uninhibited.
Claims17
A method for treating diesel engine exhaust gases comprising:
- providing an exhaust gas treatment system in an exhaust stream comprising a diesel oxidation catalyst comprised of a platinum group metal;
- a platinum group metal trap comprising cerium oxide or a perovskite material positioned downstream from said diesel oxidation catalyst adapted to trap platinum group metals released from said diesel oxidation catalyst;
- and a selective reduction catalyst (SCR) positioned downstream from said platinum group metal trap;
- and
- passing exhaust gases through said exhaust gas treatment system to convert a portion of NOx in said exhaust stream to N2 and to convert a portion of CO and HC in said exhaust stream to CO2 and H2O;
- wherein said platinum group metal trap reduces platinum contamination on said SCR catalyst in comparison with an exhaust system which does not include a platinum group metal trap.
A diesel exhaust gas treatment system comprising:
- a diesel oxidation catalyst comprising a platinum group metal positioned in an exhaust stream;
- a selective catalytic reduction (SCR) catalyst positioned downstream from said diesel oxidation catalyst;
- a platinum group metal trap comprising cerium oxide or a perovskite material positioned between said diesel oxidation catalyst and said selective catalytic reduction (SCR) catalyst and adapted to trap platinum group metals released from said diesel oxidation catalyst and reduce platinum contamination on
- said selective catalytic reduction (SCR) catalyst.
Dependencies are inferred from the claim text.