Catalyzed filter for treating exhaust gas

Passive NOx adsorber

A NOx adsorber comprising a noble metal, such as platinum, palladium, rhodium, gold, silver, iridium, ruthenium, osmium, and a small pore molecular sieve having a maximum ring size of eight tetrahedral atoms, such as aluminosilicate sieves, aluninophosphate molecular sieves and metal-substituted aluminophosphate molecular sieves. Also disclosed, is an exhaust system for internal combustion engines comprising the NOx adsorber and a method of reducing NOx in an exhaust gas using the NOx adsorber.

Catalyzed filter for treating exhaust gas

Cold start catalyst and its use in exhaust systems

A catalyst, suitable for use as a cold start catalyst, to adsorb NOx and hydrocarbons (HC), the catalyst comprising a molecular sieve catalyst having a noble metal, and a supported platinum group metal catalyst comprising one or more platinum group metals, such as platinum, palladium, rhodium, indium, and one or more inorganic oxide carriers, such as alumina, silica, titania, zirconia, ceria, niobia, tantalum oxides, molybdenum oxides, tungsten oxides. Also disclosed is use of the catalyst in an exhaust system for internal combustion engines.

Noble metal-molecular sieve catalysts

A noble metal-molecular sieve catalyst effective to adsorb NOx and hydrocarbons (HC), comprises a first molecular sieve catalyst, such as a zeolite, having a first noble metal, such as palladium and a second molecular sieve catalyst, such as a zeolite, having a second noble metal, such as palladium. The noble metal, such as palladium, is located inside pores of the molecular sieves, in an amount greater than 5 percent. The first and second molecular sieves are different. Also disclosed is a method for treating an exhaust gas using the noble metal-molecular sieve catalyst.

Catalyzed filter for treating exhaust gas

A Diesel particulate filter (DPF) comprises a wall-flow filter substrate having a mean pore size, an inlet side, an outlet side, and a porous interior there between. A catalyst composition 44 is coated from the inlet side of the substrate to form a catalysed soot filter (CSF), and has a D50 particle size distribution which is less than the mean pore size divided by 4.9 ± 0.1, and wherein the outlet side is substantially free of a catalyst coating. The mean pore size may be at least 10 or 15 µm. The D50 particle size may be not more than 2.5 or 2 µm, or between 1 and 2 µm. The porous interior may also be substantially free of a catalyst coating. The catalyst composition may be present as a single layer, and further layers could be coated from the outlet side of the filter. The catalyst coating may comprise a selective catalytic reduction (SCR) catalyst, or an ammonia slip catalyst.

Mixed template synthesis of high silica Cu-CHU

A composition comprises a synthetic zeolite having a CHA framework structure, a molar silica-to-alumina ratio SAR of 25 to 150, and an in-situ transition metal uniformly dispersed within the cavities and channels of the zeolite. The transition metal may be copper or iron. A further composition comprises synthetic zeolite containing copper, having a CHA framework structure, and a unit cell volume of 2355 to 2375 Ã 3. A further composition comprises a synthetic zeolite having a CHA framework structure, 0.1 to 5 weight percent of non-framework copper, a phase purity of at least 95% by weight, and less than 5 weight percent CuO. A method for synthesizing a zeolite comprises: preparing a mixture comprising (a) at least one source of alumina, (b) at least one source of silica, (c) a transition-metal-amine organic templating agent, (d) seed crystals, and (e) a distinct second organic templating agent, each of the templating agents being suitable for forming a CHA structure, the reaction mixture ...

Synthesis of AEI zeolite

A composition comprises a synthetic zeolite having an AEI framework structure and an in-situ transition metal dispersed within the cavities and channels of the zeolite. The invention also comprises a method for synthesizing a zeolite comprising: preparing a reaction mixture comprising (a) at least one source of alumina, (b) at least one source of silica, (c) a transition-metal-amine organic templating agent, (d) an alkali metal hydroxide, and (e) distinct second organic templating agent, wherein each of the first and second templating agents is suitable for forming an AEI framework structure and wherein the reaction mixture is essentially free of fluorine; heating the reaction mixture at crystallization conditions for a sufficient time to form zeolite crystals having an AEI framework and optionally an ITE framework and containing the transition metal. The transition metal is preferably copper or iron, and the zeolite can be incorporated into a catalyst for treating exhaust gas containing ...