摘要:
A catalyst composition is provided having a zeolite material of a CHA crystal structure and a silica to alumina mole ratio (SAR) of about 10 to about 25 and preferably having a mean crystal size of at least 1.0 microns; and a non-aluminum base metal (M), wherein said zeolite material contains said base metal in a base metal to aluminum ratio (M:Al) of about 0.10 to about 0.24.
摘要:
Provided is a catalyst comprising (a) a zeolite material having a mean crystal size of at least about 0.5 μm, having a CHA framework that contains silicon and aluminum, and having a silica-to-alumina mole ratio (SAR) of about 10 to about 25; and (b) an extra-framework promoter metal (M) disposed in said zeolite material as free and/or exchanged metal, wherein the extra-framework promoter metal is copper, iron, and mixtures thereof, and is present in a promoter metal-to-aluminum atomic ratio (M:Al) of about 0.10 to about 0.24 based on the framework aluminum; and optionally comprising (c) at least about 1 weight percent of cerium in said zeolite material, based on the total weight of the zeolite, wherein said cerium is present in a form selected from exchanged cerium ions, monomeric ceria, oligomeric ceria, and combinations thereof, provided that said oligomeric ceria has a particle size of less than 5 μm.
摘要:
Provided is a catalyst comprising (a) a zeolite material having a mean crystal size of at least about 0.5 μm, having a CHA framework that contains silicon and aluminum, and having a silica-to-alumina mole ratio (SAR) of about 10 to about 25; and (b) an extra-framework promoter metal (M) disposed in said zeolite material as free and/or exchanged metal, wherein the extra-framework promoter metal is copper, iron, and mixtures thereof, and is present in a promoter metal-to-aluminum atomic ratio (M:Al) of about 0.10 to about 0.24 based on the framework aluminum; and optionally comprising (c) at least about 1 weight percent of cerium in said zeolite material, based on the total weight of the zeolite, wherein said cerium is present in a form selected from exchanged cerium ions, monomeric ceria, oligomeric ceria, and combinations thereof, provided that said oligomeric ceria has a particle size of less than 5 μm.
摘要:
A synthetic alumino silicate zeolite catalyst containing at least one catalytically active transition metal selected from the group consisting of Cu, Fe, Hf, La, Au, In, V, lanthanides and Group VIII transition metals, which alumino silicate zeolite is a small pore aluminosilicate zeolite having a maximum ring size of eight tetrahedral atoms, wherein the mean crystallite size of the aluminosilicate zeolite determined by scanning electron microscope is >0.50 micrometer.
摘要:
An exhaust system for a lean burn internal combustion engine comprises a particulate filter (CSF), a first NOx absorbent (NOx(1)) disposed upstream of the filter and a second NOx absorbent (NOx(2)) disposed downstream of the filter.
摘要:
An exhaust system for a lean burn internal combustion engine comprises a particulate filter (CSF), a first NOx absorbent (NOx(1)) disposed upstream of the filter and a second NOx absorbent (NOx(2)) disposed downstream of the filter.
摘要:
An exhaust system for a lean burn internal combustion engine includes a particulate filter (CSF), a first NOx absorbent (NOx(1)) disposed upstream of the filter and a second NOx absorbent (NOx(2)) disposed downstream of the filter.
摘要:
Provided is a wall-flow filter coated with an SCR catalyst composition, wherein the catalyst composition contains transition metal promoted molecular sieve crystals, and wherein (i) the crystals have a mean crystalline size of about 0.5 μm to about 15 μm, (ii) the crystals are present in said composition as individual crystals, agglomerations having a mean particle size of less than about 15 μm, or a combination of said individual crystals and said agglomerations; and (iii) said molecular sieve is an aluminosilicate or a silico-aluminophosphate of a Framework Type having a maximum ring size of eight tetrahedral atoms.
摘要:
A method of coating a honeycomb monolith substrate comprising a plurality of channels with a liquid comprising a catalyst component comprises the steps of: (i) holding a honeycomb monolith substrate substantially vertically; (ii) introducing a pre-determined volume of the liquid into the substrate via open ends of the channels at a lower end of the substrate; (iii) sealingly retaining the introduced liquid within the substrate; (iv) inverting the substrate containing the retained liquid; and (v) applying a vacuum to open ends of the channels of the substrate at the inverted, lower end of the substrate to draw the liquid along the channels of the substrate.
摘要:
An exhaust system(10) for a lean-burn internal combustion engine (12) comprises a first substrate monolith (16) comprising a catalyst for oxidising nitric oxide (NO) comprising a catalytic oxidation component followed downstream by a second substrate monolith (18) which is a wall-flow filter having inlet channels and outlet channels, wherein the inlet channels comprise a NO x absorber catalyst (20) and the outlet channels comprise a catalyst for selective catalytic reduction (22) of nitrogen oxides with nitrogenous reductant.