摘要:
An extruded honeycomb catalyst for nitrogen oxide reduction according to the selective catalytic reduction (SCR) method in exhaust gases from motor vehicles includes an extruded active carrier in honeycomb form having a first SCR catalytically active component and with a plurality of channels through which the exhaust gas flows during operation, and a washcoat coating having a second SCR catalytically active component being applied to the extruded body, wherein the first SCR catalytically active component and the second SCR catalytically active component are each independently one of: (i) vanadium catalyst with vanadium as catalytically active component; (ii) mixed-oxide catalyst with one or more oxides, in particular those of transition metals or lanthanides as catalytically active component; and (iii) an Fe- or a Cu-zeolite catalyst.
摘要:
The present invention provides an iron-loaded aluminosilicate zeolite having a maximum pore opening defined by eight tetrahedral atoms and having the framework type CHA, AEI, AFX, ERI or LTA, wherein the iron (Fe) is present in a range of from about 0.5 to about 5.0 wt. % based on the total weight of the iron-loaded aluminosilicate zeolite, wherein an ultraviolet-visible absorbance spectrum of the iron-loaded synthetic aluminosilicate zeolite comprises a band at approximately 280 nm, wherein a ratio of an integral, peak-fitted ultraviolet-visible absorbance signal measured in arbitrary units (a.u.) for the band at approximately 280 nm to an integral peak-fitted ultraviolet-visible absorbance signal measured in arbitrary units (a.u.) for a band at approximately 340 nm is >about 2. The present invention further provides a method of making an metal-loaded aluminosilicate zeolite having a maximum pore opening defined by eight tetrahedral atoms from pre-existing aluminosilicate zeolite crystallites, wherein the metal is present in a range of from 0.5 to 5.0 wt. % based on the total weight of the metal-loaded aluminosilicate zeolite.
摘要:
In order to specify a catalytic converter, especially SCR catalytic converter, with maximum catalytic activity, this catalytic converter has at least one catalytically active component and additionally at least one porous inorganic filler component having meso- or macroporosity. The organic porous filler component has a proportion of about 5 to 50% by weight. More particularly, a diatomaceous earth or a pillared clay material is used as the porous inorganic filler component.
摘要:
A filter incorporates a catalyst for the Selective Catalytic Reduction (SCR) of NOx gases and removal of particulate matter from the exhaust gas of a lean burn combustion engine, wherein the catalyst includes a vanadate component having an alkaline earth metal, a transition metal, a rare earth metal, or combinations thereof. The vanadate component may be iron vanadate. The filter includes a supported vanadate component disposed on a wall-flow filter. The method of making the filter includes applying an aqueous mixture of the supported vanadate component as a washcoat on the wall-flow filter or extruding a composition containing the supported vanadate component. The method of treating exhaust gases from an engine includes contacting the exhaust gas with the catalyst including the vanadate component.
摘要:
A wall-flow filter comprises a catalyst for converting oxides of nitrogen in the presence of a reducing agent, which wall-flow filter comprising an extruded solid body comprising: 10-95% by weight of at least one binder/matrix component; 5-90% by weight of a zeolitic molecular sieve, a non-zeolitic molecular sieve or a mixture of any two or more thereof; and 0-80% by weight optionally stabilized ceria, which catalyst comprising at least one metal, wherein: the at least one metal is present throughout the extruded solid body alone or in combination with: is also present in a higher concentration at a surface of the extruded solid body; is also carried in one or more coating layer(s) on a surface of the extruded solid body; or both.
摘要:
An extruded honeycomb catalyst for nitrogen oxide reduction according to the selective catalytic reduction (SCR) method in exhaust gases from motor vehicles includes an extruded active carrier in honeycomb form having a first SCR catalytically active component and with a plurality of channels through which the exhaust gas flows during operation, and a washcoat coating having a second SCR catalytically active component being applied to the extruded body, wherein the first SCR catalytically active component and the second SCR catalytically active component are each independently one of: (i) vanadium catalyst with vanadium as catalytically active component; (ii) mixed-oxide catalyst with one or more oxides, in particular those of transition metals or lanthanides as catalytically active component; and (iii) an Fe- or a Cu-zeolite catalyst.
摘要:
A filter incorporates a catalyst for the Selective Catalytic Reduction (SCR) of NOx gases and removal of particulate matter from the exhaust gas of a lean burn combustion engine, wherein the catalyst includes a vanadate component having an alkaline earth metal, a transition metal, a rare earth metal, or combinations thereof. The vanadate component may be iron vanadate. The filter includes a supported vanadate component disposed on a wall-flow filter. The method of making the filter includes applying an aqueous mixture of the supported vanadate component as a washcoat on the wall-flow filter or extruding a composition containing the supported vanadate component. The method of treating exhaust gases from an engine includes contacting the exhaust gas with the catalyst including the vanadate component.
摘要:
To be able to produce an SCR catalyst (2), in particular one having a zeolite fraction (Z) as catalytically active fraction, in a reliable process and at the same time achieve good catalytic activity of the catalyst (2), an inorganic binder fraction (B) which is catalytically inactive in the starting state and has been treated to develop catalytic activity is mixed into a catalyst composition (4). The inorganic binder component for the binder fraction (B) is, in the starting state, preferably porous particles (10), in particular diatomaceous earth, which display mesoporosity. To effect catalytic activation, the individual particles (10) are either coated with a catalytically active layer (12) or transformed into a catalytically active zeolite (14) with maintenance of the mesoporosity.
摘要:
Provided is a catalyst composition for treating exhaust gas comprising a blend of a first component and second component, wherein the first component is an aluminosilicate or ferrosilicate molecular sieve component wherein the molecular sieve is either in H+ form or is ion exchanged with one or more transition metals, and the second component is a vanadium oxide supported on a metal oxide support selected from alumina, titania, zirconia, cella, silica, and combinations thereof. Also provided are methods, systems, and catalytic articles incorporating or utilizing such catalyst blends.
摘要:
Systems and methods of continuous operation of a urea-SCR system at low temperatures (200-350° C.) in the presence of high SOx containing flue gas are described. The methods comprise introducing a solution of urea and an NO2 forming compound, preferably an alkaline earth metal nitrate, into an exhaust stream before the exhaust stream contacts an SCR catalyst.