Abstract: A catalyst system for use with an internal combustion engine to provide emissions reductions under lean and stoichiometric operating conditions. The catalyst system comprises a first catalyst comprised of a newly developed Perovskite-based formulation having an ABO3 crystal structure designed to bring the precious metal and NOx trapping elements close together. The first catalyst acts primarily to maximize the reduction of emissions under lean operating conditions. The catalyst system also comprises a second catalyst comprised of precious metals which acts primarily to maximize the reduction of emissions under stoichiometric conditions.

Abstract: A catalyst system for use with an internal combustion engine to provide emissions reductions under lean and stoichiometric operating conditions. The catalyst system comprises a first catalyst comprised of a newly developed Perovskite-based formulation having an ABO3 crystal structure designed to bring the precious metal and NOx trapping elements close together. The first catalyst acts primarily to maximize the reduction of emissions under lean operating conditions. The catalyst system also comprises a second catalyst comprised of precious metals which acts primarily to maximize the reduction of emissions under stoichiometric conditions.

Abstract: A catalyst system to provide emission reductions under lean and stoichiometric conditions. The catalyst system comprises a forward catalyst having a first cerium-free zone including oxides of aluminum, alkali metals and alkaline earth metals and precious metals and a second zone with a lower loading of precious metals, oxides of aluminum, alkali metals or alkaline earth metals. This forward catalyst stores NOx emissions under lean conditions for subsequent reduction and converts HC, CO and NOx during stoichiometric operation. The second downstream catalyst includes precious metals, reduces emissions under stoichiometric conditions, and stores any residual NOx emitted from the first catalyst for subsequent reduction. In another embodiment, a forward catalyst has top and bottom layers designed to reduce emissions under lean conditions. In this embodiment, a second downstream catalyst is used to reduce emissions under stoichiometric conditions.

Abstract: A catalyst system for use with an internal combustion engine to provide emissions reductions under lean and stoichiometric operating conditions. The catalyst system comprises a first catalyst comprised of a newly developed Perovskite-based formulation having an ABO3 crystal structure designed to bring the precious metal and NOx trapping elements close together. The first catalyst acts primarily to maximize the reduction of emissions under lean operating conditions. The catalyst system also comprises a second catalyst comprised of precious metals which acts primarily to maximize the reduction of emissions under stoichiometric conditions.

Abstract: An automobile exhaust system includes a catalytic converter, a NOx trap, and a sulfur oxide trap. The sulfur oxide trap improves the efficiency of the NOx trap. Sulfur oxide has a deleterious effect on the performance of nitrogen oxide traps. The sulfur oxide trap comprises a monolithic substrate which is over-coated with an aluminum oxide layer and a mixed oxide layer of calcium oxide and magnesium oxide. In a variation, a sulfur oxide trap is integrated with a nitrogen oxide trap by coating the catalyst contained within a nitrogen oxide trap with a mixed oxide layer of calcium oxide and magnesium oxide. In each embodiment, the sulfur oxide trap can be regenerated by heating at elevated temperature for a short time period.

Abstract: An integrated lean NOx trap. The integrated lean NOx trap includes a lean NOx trap containing a composite metal oxide mixture consisting essentially of about 80-100 wt % stoichiometric spinel MgAl2O4 and between about 0-20 wt % of CeO2 or CeO2—ZrO2. A method for removing NOx and SOx impurities from exhaust gases using the integrated lean NOx trap is also described.

Abstract: The present invention provides a composition and method for storing and reducing NOx from lean burn internal combustion engines. The present invention uses composite metal oxides, in spinel structure, in conjunction with the typical lean NOx trap formulation to form an integrated lean NOx trap. The composite metal oxides in spinel structure act primarily as a SOx trapping element and also secondarily as a NOx trapping element within the integrated LNT. In this integrated LNT, the sulfur is trapped and released in a way that does not allow the sulfur to go to the primary NOx trapping element an alkali or earth metal - and thus prevents the integrated lean NOx trap from becoming poisoned, thereby leaving more reactive sites for NOx trapping and conversion.

Abstract: The invention is a method of manufacturing a three-way catalyst and the catalyst as well as its use for treating exhaust gas generated by a gasoline internal combustion engine. The catalyst composition comprises a mixture of particles of three different materials. More specifically, it includes a mixture of calcined ceria/zirconia particles impregnated with platinum together with palladium, other calcined ceria/zirconia particles impregnated with only rhodium precious metal, and alumina particles not impregnated with precious metal.

Abstract: The present invention provides a composition and method for storing and reducing NOx for lean burn internal combustion engines. The present invention uses composite metal oxides, in spinel structure, in conjunction with a typical LNT formulation to form an integrated LNT. The composite metal oxides in spinel structure act primarily as a SOx trapping element and also a secondarily NOx trapping element within the integrated LNT. In this integrated LNT, the sulfur is trapped and released in a way that does not allow the sulfur to go to the primary NOx trapping element, i.e. the alkali or alkali earth metal oxides, to poison the integrated LNT; thereby, leaving more reactive sites for the NOx trapping and conversion.

Abstract: The invention is a method of treating exhaust gases generated by an internal combustion engine using a NOx trap in the exhaust flow system. The method comprises locating a nitrogen oxide trap in the exhaust gas passage and cycling the air/fuel ratio of the exhaust gases entering the trap between lean and rich, such that the trap absorbs nitrogen oxides during the lean cycle and desorbs the nitrogen oxides when the concentration of the oxygen in the exhaust flow is lowered as during a rich cycle. The trap comprises: (a) a porous support material comprising mostly &ggr;-alumina; (b) a sulfur-suppressing metal selected from the group consisting of cesium, zinc and a combination of cesium and zinc; (c) a precious metal; and (d) a NOx sorption metal such as barium, the metals being deposited in the support material, the amount of the metals being individually dependent on the weight of the support material.