摘要:
Provided is a catalyst for the selective reduction of NOx comprising a two molecular sieve materials having a CHA structure, wherein the first molecular sieve has a mean crystal size of about 0.01 to 1 μm and the second molecular sieve has a mean crystal size of about 1-5 μm, and wherein the first molecular sieve contains a first extra-framework metal, the second molecular sieve contains a second extra-framework metal, and wherein said first and second extra-framework metals are independently selected from the group consisting of cesium, copper, nickel, zinc, iron, tin, tungsten, molybdenum, cobalt, bismuth, titanium, zirconium, antimony, manganese, chromium, vanadium, niobium, and combinations thereof.
摘要:
A positive ignition engine comprising an exhaust system, which comprises a catalysed filter for filtering particulate matter from exhaust gas emitted from a positive ignition internal combustion engine, which filter comprising a porous substrate having a total substrate length and having inlet surfaces and outlet surfaces, wherein the inlet surfaces are separated from the outlet surfaces by a first porous structure containing pores of a first mean pore size, wherein the porous substrate is coated with a washcoat composition which is a NOx absorber catalyst washcoat composition comprising at least one precious metal; or a selective catalytic reduction (SCR) catalyst washcoat composition, wherein a second porous structure of the washcoated porous substrate contains pores of a second mean pore size, wherein the second mean pore size is less than the first mean pore size, which NOx absorber catalyst washcoat or SCR catalyst washcoat being axially arranged on the porous substrate as a first zone comprising the inlet surfaces of a first substrate length less than the total substrate length and a second zone comprising the outlet surfaces of a second substrate length less than the total substrate length, wherein the sum of the substrate length in the first zone and the substrate length in the second zone is ≧100%, wherein: (i) a washcoat loading in the first zone >second zone; or (ii) where the washcoat composition is a NOx absorber catalyst washcoat composition, both a washcoat loading and a total precious metal loading in the first zone >second zone, and wherein the first zone is disposed upstream of the second zone.
摘要:
A catalysed substrate monolith 12 for use in treating exhaust gas emitted from a lean-burn internal combustion engine, which catalysed substrate monolith 12 comprising a first washcoat coating 16 and a second washcoat coating 18, wherein the first washcoat coating comprises a catalyst composition comprising at least one platinum group metal (PGM) and at least one support material for the at least one PGM, wherein at least one PGM in the first washcoat coating is liable to volatilise when the first washcoat coating is exposed to relatively extreme conditions including relatively high temperatures, wherein the second washcoat coating comprises at least one metal oxide for trapping volatilised PGM and wherein the second washcoat coating is oriented to contact exhaust gas that has contacted the first washcoat coating.
摘要:
The invention provides an exhaust gas cleaning oxidation catalyst and in particular to an oxidation catalyst for cleaning the exhaust gas discharged from internal combustion engines of compression ignition type (particularly diesel engines). The invention further relates to a catalysed substrate monolith comprising an oxidising catalyst on a substrate monolith for use in treating exhaust gas emitted from a lean-burn internal combustion engine. In particular, the invention relates to a catalysed substrate monolith comprising a first washcoat coating and a second washcoat coating, wherein the second washcoat coating is disposed in a layer above the first washcoat coating.
摘要:
A catalysed substrate monolith 12 for use in treating exhaust gas emitted from a lean-burn internal combustion engine, which catalysed substrate monolith 12 comprising a first washcoat coating 16 and a second washcoat coating 18, wherein the first washcoat coating comprises a catalyst composition comprising at least one platinum group metal (PGM) and at least one support material for the at least one PGM, wherein at least one PGM in the first washcoat coating is liable to volatilise when the first washcoat coating is exposed to relatively extreme conditions including relatively high temperatures, wherein the second washcoat coating comprises at least one metal oxide for trapping volatilised PGM and wherein the second washcoat coating is oriented to contact exhaust gas that has contacted the first washcoat coating.
摘要:
A catalyst composition is provided wherein the composition includes a zeolite having a non-phosphorous CHA crystal structure and having a mean crystalline size of about 1 to about 5 microns; and at least one non-aluminum base metal present in an amount sufficient to achieve a NOx conversion of at least about 65% at a temperature of at least 450° C.
摘要:
A catalysed substrate monolith 12 for use in treating exhaust gas emitted from a lean-burn internal combustion engine, which catalysed substrate monolith 12 comprising a first washcoat coating 16 and a second washcoat coating 18, wherein the first washcoat coating comprises a catalyst composition comprising at least one platinum group metal (PGM) and at least one support material for the at least one PGM, wherein at least one PGM in the first washcoat coating is liable to volatilise when the first washcoat coating is exposed to relatively extreme conditions including relatively high temperatures, wherein the second washcoat coating comprises at least one metal oxide for trapping volatilised PGM and wherein the second washcoat coating is oriented to contact exhaust gas that has contacted the first washcoat coating.
摘要:
Provided is a catalyst for the selective reduction of NOx comprising a two molecular sieve materials having a CHA structure, wherein the first molecular sieve has a mean crystal size of about 0.01 to 1 μm and the second molecular sieve has a mean crystal size of about 1-5 μm, and wherein the first molecular sieve contains a first extra-framework metal, the second molecular sieve contains a second extra-framework metal, and wherein said first and second extra-framework metals are independently selected from the group consisting of cesium, copper, nickel, zinc, iron, tin, tungsten, molybdenum, cobalt, bismuth, titanium, zirconium, antimony, manganese, chromium, vanadium, niobium, and combinations thereof.
摘要:
The invention provides an exhaust gas cleaning oxidation catalyst and in particular to an oxidation catalyst for cleaning the exhaust gas discharged from internal combustion engines of compression ignition type (particularly diesel engines). The invention further relates to a catalysed substrate monolith comprising an oxidising catalyst on a substrate monolith for use in treating exhaust gas emitted from a lean-burn internal combustion engine. In particular, the invention relates to a catalysed substrate monolith comprising a first washcoat coating and a second washcoat coating, wherein the second washcoat coating is disposed in a layer above the first washcoat coating.
摘要:
The invention provides an exhaust gas cleaning oxidation catalyst and in particular to an oxidation catalyst for cleaning the exhaust gas discharged from internal combustion engines of compression ignition type (particularly diesel engines). The invention further relates to a catalysed substrate monolith comprising an oxidising catalyst on a substrate monolith for use in treating exhaust gas emitted from a lean-burn internal combustion engine. In particular, the invention relates to a catalysed substrate monolith comprising a first washcoat coating and a second washcoat coating, wherein the second washcoat coating is disposed in a layer above the first washcoat coating.