摘要:
One embodiment of the invention may include a method comprising providing a product comprising a substrate comprising a perovskite catalyst, NOx stored in or on the substrate and particulate matter in or on the substrate; releasing at least some of the stored NOx and oxidizing the released NOx to form NO2, and reacting the NO2 with carbon in the particulate matter to form at least one of CO or CO2.
摘要:
A bi-functional catalyst material, a SCR converter that includes the bi-functional catalyst material, an exhaust aftertreatment system that includes the SCR converter, and a method for removing NOX contained in an exhaust flow produced by a lean-burn engine are disclosed. The bi-functional catalyst material can (1) oxidize NO to NO2 and (2) selectively reduce NOX to N2 when exposed to an exhaust mixture that comprises the exhaust flow from the lean-burn engine and a suitable reductant. The bi-functional catalyst material comprises metal oxide particles selected from the group consisting of perovskite oxide particles and manganese-based mixed metal oxide particles dispersed on a selective catalytic reduction (SCR) catalyst.
摘要:
One embodiment of the invention may include a product comprising a catalyst combination comprising a perovskite catalyst and a second catalyst that is not a perovskite catalyst.
摘要:
Ammonia in a gas stream comprising oxygen and nitrogen may be effectively completely oxidized to a mixture of NO and NO2 for further processing to nitric acid. The gas stream is flowed over fine particles of La1-xSrxCoO3 and/or La1-xSrxMnO3, and/or La1-xSrxFeO3 where x=about 0.1, 0.2, or 0.3. The particles are supported as catalyst layers on gas stream-contacting surfaces of a flow-through catalyzed oxidation reactor. These relatively inexpensive perovskite-type materials may be used to promote oxidation of ammonia at temperatures below about 450° C. to about 500° C. to selectively produce a mixture of NO and NO2. This mixture is suitable for further oxidation to NO2 for adsorption into water to make nitric acid.
摘要:
A method for removing NOX from an oxygen-rich exhaust flow produced by a combustion source that is combusting a lean mixture of air and fuel may include passing the oxygen-rich exhaust flow through an exhaust aftertreatment system that includes a NOX oxidation catalyst that includes perovskite oxide particles, a NOX storage catalyst, and a NOX reduction catalyst.
摘要:
An exhaust aftertreatment system for a lean-burn engine may include a lean NOX trap that comprises a catalyst material. The catalyst material may remove NOX gases from the engine-out exhaust emitted from the lean-burn engine. The catalyst material may include a NOX oxidation catalyst that comprises a perovskite compound.
摘要:
One embodiment of the invention may include a product comprising a catalyst combination comprising a perovskite catalyst and a second catalyst that is not a perovskite catalyst.
摘要:
An internal combustion engine configured to operate in a compression-ignition combustion mode includes an exhaust aftertreatment system. The exhaust aftertreatment system includes a catalyst device fluidly coupled upstream of an ammonia-selective catalytic reduction device. The, catalyst device includes first, second, and third elements fluidly coupled in series. The first element includes a three-way catalytic element, the second element includes a NOx adsorber, and the third element includes an oxidation catalytic element.
摘要:
One embodiment of the invention includes a method of treating a gas stream comprising flowing the gas stream over a hydrocarbon reduction and NOx reduction catalyst first, and thereafter flowing the gas over a perovskite and NOx trap material for NOx oxidation and storage. In one embodiment, the hydrocarbon reduction and NOx reduction catalyst may include palladium. In one embodiment, the perovskite catalyst may have the general formula ABO3, AA′BO3, ABB′O3, or AA′BB′O3. The perovskite catalyst may be the only catalyst or a second non-perovskite catalyst may include at least one of palladium, platinum, rhodium, ruthenium or a catalyst system including one or more of the same or alloys thereof. In one embodiment, the NOx trap material may include at least one of alkali metals, alkaline earth metals such as barium, calcium, potassium, or sodium.