Abstract:
The present disclosure generally provides low-temperature nitrogen oxides (NOx) adsorbers used in the treatment of a NOx-containing exhaust gas stream and to methods of preparing and using the same. In particular, the NOx adsorber composition includes an active metal and a metal oxide support, wherein the metal oxide support includes greater than 50% by weight ceria based on the total weight of the NOx adsorber composition, and wherein the active metal includes about 0.01% to about 5% by weight ruthenium based on the total weight of the NOx adsorber composition.
Abstract:
A catalyst for the treatment of exhaust gas emissions is disclosed. The catalyst can comprise 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 CeO2 is present in the form of crystallites that are hydrothermally stable and have an average crystallite size less than 160 Å after aging at 950° C. for 5 hours in 2% O2 and 10% steam in N2.
Abstract:
The present invention is directed to selective catalytic reduction catalysts that combine SCR activity with NOx absorber activity. In particular, the disclosed catalytic article includes a substrate having a first and a second material disposed thereon, wherein the first material includes a selective catalytic reduction (SCR) catalyst composition and the second material includes a nitrogen oxides (NOx) absorber composition, wherein the NOx absorber composition does not substantially oxidize ammonia, and wherein the catalytic article is effective to abate NOx from an engine exhaust gas stream. Emission treatment systems for treating an exhaust gas including a catalytic article of the invention are provided, particularly systems that include an injector adapted for the addition of ammonia to the exhaust gas stream located upstream of the catalytic article.
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:
The present invention relates to a process for preparing a catalyst, at least comprising the steps of adding a protecting agent to an aqueous solution of a metal precursor to give a mixture (M1), adding a reducing agent to mixture (M1) to give a mixture (M2), adding a support material to mixture (M2) to give a mixture (M3), adjusting the pH of mixture (M3), and separating the solid and liquid phase of mixture (M3). Furthermore, the present invention relates to the catalyst as such and its use as diesel oxidation catalyst.
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:
The present disclosure is directed to Low Temperature NOx-Absorber (LT-NA) catalyst compositions, catalyst articles, and an emission treatment system for treating an exhaust gas, each including the LT-NA catalyst compositions. Further provided are methods for reducing a NOx level in an exhaust gas stream using the catalyst article. In particular, the LT-NA compositions include a zeolite containing a first metal component including palladium and a second metal component which is an alkaline earth metal component, an oxide of an alkaline earth metal component, a rare earth metal component, an oxide of a rare earth metal component, or a combination thereof. The LT-NA compositions exhibit increased low temperature NOx adsorption capacity and enhanced hydrothermal stability.
Abstract:
The present disclosure generally provides low-temperature nitrogen oxides (NOx) adsorbers used in the treatment of a NOx-containing exhaust gas stream and to methods of preparing and using the same. In particular, the NOx adsorber composition includes an active metal and a metal oxide support, wherein the metal oxide support includes greater than 50% by weight ceria based on the total weight of the NOx adsorber composition, and wherein the active metal includes about 0.01% to about 5% by weight ruthenium based on the total weight of the NOx adsorber composition.
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:
The present invention provides an oxidation catalyst composition suitable for at least partial conversion of gaseous hydrocarbon emissions, e.g., methane. The oxidation catalyst composition includes at least one platinum group metal (PGM) component supported onto a porous zirconia-containing material that provides an effect on hydrocarbon conversion activity. The porous zirconia-containing material is at least 90% by weight in the monoclinic phase. Furthermore, the PGM component can comprise at least one platinum group metal in the form of colloidally deposited nanoparticles. The oxidation catalyst composition can be used in the treatment of emissions from lean compressed natural gas engines.