摘要:
An oxidation catalyst for treating an exhaust gas from a diesel engine and an exhaust system comprising the oxidation catalyst are described. The oxidation catalyst comprises a washcoat region disposed on a substrate, wherein the washcoat region comprises: palladium (Pd), gold (Au) and a support material, wherein the palladium (Pd) and gold (Au) are supported on the support material; and a molecular sieve catalyst, wherein the molecular sieve catalyst comprises a noble metal and a molecular sieve.
摘要:
Hydrocarbon (HC) traps are disclosed. The HC trap may include a first zeolite material having an average pore diameter of at least 5.0 angstroms and configured to trap hydrocarbons from an exhaust stream and to release at least a portion of the trapped hydrocarbons at a temperature of at least 225° C. The HC trap may also include a second zeolite material having an average pore diameter of less than 5.0 angstroms or larger than 7.0 angstroms. One or both of the zeolite materials may include metal ions, such as transition, Group 1A, or platinum group metals. The HC trap may include two or more discrete layers of zeolite materials or the two or more zeolite materials may be mixed. The multiple zeolite HC trap may form coke molecules having a relatively low combustion temperature, such as below 500° C.
摘要:
A heterogeneous catalyst article having at least one combination of a first molecular sieve having a medium pore, large pore, or meso-pore crystal structure and optionally containing a first metal, and a second molecular sieve having a small pore crystal structure and optionally containing a second metal, and a monolith substrate onto or within which said catalytic component is incorporated, wherein the combination of the first and second molecular sieves is a blend, a plurality of layers, and/or a plurality of zones.
摘要:
A catalyst for selective catalytic reduction of NOx having one or more transition metals selected from Cr, Mn, Fe, Co, Ce, Ni, Cu, Zn, Ga, Mo, Ru, Rh, Pd, Ag, In, Sn, Re, Ir, Pt, and mixtures thereof supported on a support, wherein the support has a molecular sieve having at least one intergrowth phase having at least two different small-pore, three-dimensional framework structures.
摘要:
A cold start catalyst is disclosed. The cold start catalyst comprises a zeolite catalyst and a supported platinum group metal catalyst. The zeolite catalyst comprises a base metal, a noble metal, and a zeolite. The supported platinum group metal catalyst comprises one or more platinum group metals and one or more inorganic oxide carriers. The invention also includes an exhaust system comprising the cold start catalyst. The cold start catalyst and the process result in improved NOx storage and NOx conversion, improved hydrocarbon storage and conversion, and improved CO oxidation through the cold start period.
摘要:
A catalyst for selective catalytic reduction of NOx having one or more transition metals selected from Cr, Mn, Fe, Co, Ce, Ni, Cu, Zn, Ga, Mo, Ru, Rh, Pd, Ag, In, Sn, Re, Ir, Pt, and mixtures thereof supported on a support, wherein the support has a molecular sieve having at least one intergrowth phase having at least two different small-pore, three-dimensional framework structures.
摘要:
A heterogeneous catalyst article having at least one combination of a first molecular sieve having a medium pore, large pore, or meso-pore crystal structure and optionally containing a first metal, and a second molecular sieve having a small pore crystal structure and optionally containing a second metal, and a monolith substrate onto or within which said catalytic component is incorporated, wherein the combination of the first and second molecular sieves is a blend, a plurality of layers, and/or a plurality of zones.
摘要:
A cold start catalyst is disclosed. The cold start catalyst comprises a zeolite catalyst and a supported platinum group metal catalyst. The zeolite catalyst comprises a base metal, a noble metal, and a zeolite. The supported platinum group metal catalyst comprises one or more platinum group metals and one or more inorganic oxide carriers. The invention also includes an exhaust system comprising the cold start catalyst. The cold start catalyst and the process result in improved NOx storage and NOx conversion, improved hydrocarbon storage and conversion, and improved CO oxidation through the cold start period.
摘要:
Catalyst articles having a first zone containing a first SCR catalyst and a second zone containing an ammonia slip catalyst (ASC), where the ammonia slip catalyst contains a second SCR catalyst and an oxidation catalyst, and the ASC has DOC functionality, where the first zone is located on the inlet side of the substrate and the second zone is located in the outlet side of the substrate are disclosed. The catalytic articles are useful for selective catalytic reduction (SCR) of NOx in exhaust gases, in reducing the amount of ammonia slip and in oxidizing organic residues. Exhaust systems containing the catalyst articles and methods of using the catalytic articles in an SCR process, where the amount of ammonia slip is reduced and hydrocarbon are oxidized by the ASC catalyst, are also described.