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 synthetic aluminosilicate 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 aluminosilicate 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:
A method of forming an inorganic oxide coating on a monolith article is disclosed. The coated monolith article is suitable for the treatment of an exhaust gas. The method comprises spraying, as a dry particulate aerosol, inorganic particles comprising an aluminosilicate zeolite having a SAR of greater than 100:1 and a silicone resin to form a coating layer. The present invention also provides an uncalcined porous monolith article for use in forming a monolith article for the treatment of an exhaust gas. The uncalcined monolith article comprises a dry particulate composition comprising inorganic particles and a silicone resin.
摘要:
A catalytic composition for treating a NOx-containing exhaust gas, wherein the composition comprises a copper-substituted zeolite comprising: i) Ce in a total amount of about 0.1 to about 200 g/ft3; and ii) Mn in a total amount of about 0.1 to about 200 g/ft3.
摘要:
SCR-active molecular-sieve based catalysts with improved low-temperature performance are made by heating a molecular-sieve in a non-oxidizing atmosphere with steam (hydrothermal treatment), or in a reducing atmosphere without steam (thermal treatment), at a temperature in the range of 600-900° C. for a time period from 5 minutes to two hours. The resulting SCR-active iron-containing molecular sieves exhibit a selective catalytic reduction of nitrogen oxides with NH3 or urea at 250° C. that is at least 50% greater than if the iron-containing molecular-sieve were calcined at 500° C. for two hours without performing the hydrothermal or thermal treatment.
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:
Catalyst compositions and methods of preparation comprising: preparing a promoter metal-molecular sieve catalyst composition comprising a promoter metal and a molecular sieve; and incorporating an iron salt into the promoter metal-molecular sieve catalyst composition.
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:
An exhaust system for a compression ignition engine comprising: a water adsorbent material; and a catalyst composition for treating an exhaust gas pollutant produced by the compression ignition engine; wherein the water adsorbent material is: (i) arranged to contact exhaust gas from the compression ignition engine before the catalyst composition; and (ii) in thermal communication with the catalyst composition.
摘要:
Provided is a method for reducing N2O emissions in an exhaust gas comprising contacting an exhaust gas containing NH3 and an inlet NO concentration with an SCR catalyst composition containing small pore zeolite having an SAR of about 3 to about 15 and having about 1-5 wt. % of an exchanged transition metal.