Abstract:
Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.
Abstract:
Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.
Abstract:
Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.
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:
A lean NOx 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 (NOx) 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 CeO2 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% O2 and 10% steam in N2.
Abstract:
Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stability at high-reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica-to-alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.
Abstract:
Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.
Abstract:
The present disclosure provides SCR catalyst compositions, catalyst articles, and catalyst systems, as well as methods of reducing the amount of NOx present in an engine exhaust gas, particularly exhaust from a gasoline engine. The catalyst compositions particularly can comprise a doped ceria substrate, particularly a ceria support doped with at least a niobia component, and optionally further doped with a further material, particularly a base metal oxide (BMO).
Abstract:
The invention provides a selective catalytic reduction (SCR) catalyst effective in the abatement of nitrogen oxides (NOx), the SCR catalyst comprising a metal-promoted molecular sieve promoted with a metal selected from iron, copper, and combinations thereof, wherein the metal is present in an amount of 2.6% by weight or less on an oxide basis based on the total weight of the metal-promoted molecular sieve. A catalyst article, an exhaust gas treatment system method, and a method treating an exhaust gas stream, each comprising the SCR catalyst of the invention, are also provided. The SCR catalyst is particularly useful for treatment of exhaust from a lean burn gasoline engine.
Abstract:
Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.