Abstract:
Emissions treatment systems of combustion engines are provided, which comprise a platinum-containing catalyst that is degreened during production, which is before exposure to operating conditions of a vehicle having a diesel engine. The platinum-containing catalyst, in the form of a platinum component on a high surface area refractory metal oxide support, exhibits a vibration frequency of about 2085 to about 2105 cm−1 as measured by CO-DRIFTS. Such catalytic material is essentially-free of platinum oxide species found at greater than about 2110 cm−1 as measured by CO-DRIFTS. Such catalysts can provide excellent and consistent conversion of nitrogen oxide (NO) to nitrogen dioxide (NO2).
Abstract:
A layered diesel oxidation catalyst (DOC) comprises: a) a carrier substrate; b) a diesel oxidation catalytic material comprising bl)a first layer located on the carrier substrate, the first layer comprising palladium impregnated on a support material comprising ceria in an amount of at least 45 weight% based on the total weight of the support material, and optionally comprising platinum; b2) a second layer located on the first layer, the second layer comprising palladium and platinum each impregnated on a support material comprising a metal oxide; wherein the platinum to palladium weight ratio of the first layer is lower than the platinum to palladium weight ratio of the second layer.
Abstract:
Diesel oxidation catalysts, catalytic articles, methods of making catalytic articles, emissions treatment systems and methods of treating an exhaust gas stream using the catalytic articles for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC) and carbon monoxide (CO) are described. Specific catalytic articles comprising a substrate with a first washcoat layer comprising greater than or equal to about 2% by weight palladium dispersed on a ceria support and a second washcoat layer comprising a platinum group metal and a refractory metal oxide are described.
Abstract:
A lean NO x trap for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC), and carbon monoxide (CO), and the trapping and reduction of nitrogen oxides (NO x ) is disclosed. Nitrogen oxide storage catalysts can comprise a layer on a substrate including ceria-alumina particles having a ceria phase present in a weight percent of the composite in the range of about 20% to about 80% on an oxide basis, an alkaline earth metal component supported on the ceria-alumina particles, wherein the CeO 2 is present in the form of crystallites that are hydrothermally stable and have an average crystallite size less than 130 Å after aging at 950°C for 5 hours in 2% O 2 and 10% steam in N 2 .
Abstract:
Diesel oxidation catalysts, catalytic articles, methods of making catalytic articles, emissions treatment systems and methods of treating an exhaust gas stream using the catalytic articles for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC) and carbon monoxide (CO) are described. Specific catalytic articles comprising a substrate with a first washcoat layer comprising greater than or equal to about 2% by weight palladium dispersed on a ceria support and a second washcoat layer comprising a platinum group metal and a refractory metal oxide are described.
Abstract:
Described is a process for the preparation of a catalyst comprising the steps of: (i) providing one or more support materials; (ii) providing one or more polymers on the support material; and (iii) providing one or more metals on the one or more supported polymers; wherein in step (ii) the one or more polymers do not comprise cross-linked polymers and/or polymers which have been reacted with a cross-linking agent. Also described is a catalyst obtained or obtainable according to said process, as well as the use of the catalyst, in particular in a method for the treatment of automobile engine exhaust gas.