Patent classifications
B01D2255/50
A SELECTIVE CATALYTIC REDUCTION CATALYST ON A FILTER
The present invention relates to a selective catalytic reduction catalyst comprising a porous wall-flow filter substrate; wherein in the pores of the porous internal walls and on the surface of the porous internal walls, the catalyst comprises a selective catalytic reduction coating comprising a selective catalytic reduction component comprising a zeolitic material comprising one or more of copper and iron. The present invention further relates to a process for preparing a selective catalytic reduction catalyst using particles of a carbon-containing additive and an aqueous mixture comprising said particles of a carbon-containing additive.
SELECTIVE REDUCING CATALYST FOR DIESELS AND DIESEL EXHAUST GAS PURIFICATION APPARATUS
Provided are a selective reducing catalyst for diesels and a diesel exhaust gas purification apparatus in which deterioration of NO.sub.x removal performance due to phosphorus poisoning is less likely to occur.
The selective reducing catalyst for diesels is arranged in a diesel engine, adsorbs ammonia and brings the ammonia into contact with nitrogen oxides in an exhaust gas discharged from a diesel engine to perform reduction, the selective reducing catalyst comprises: a catalyst carrier; a catalyst region provided on at least the catalyst carrier; and a phosphorus trapping region provided on at least the catalyst region, wherein the catalyst region comprises one or more selected from the group consisting of a zeolite-based catalyst containing at least zeolite and a transition metal element supported on the zeolite, a W—Ce—Zr composite oxide-based catalyst, and a vanadium-based catalyst, and the phosphorus trapping region comprises at least one or more selected from the group consisting of alumina and a rare earth-based basic oxide.
Catalyst for Adsorbing Hydrocarbon and Hydrocarbon Trap Comprising the Same
A catalyst for adsorbing hydrocarbon includes a first catalyst configured to adsorb short-chain hydrocarbons and including zeolites having a pore size of about 0.30 nm to about 0.44 nm and a second catalyst configured to adsorb a long-chain hydrocarbon and including zeolites ion-exchanged with a transition metal. The catalyst can be coated on a substrate of a hydrocarbon trap.
Combined NOx absorber and SCR catalyst
The present invention is directed to selective catalytic reduction catalysts that combine SCR activity with NOx absorber activity. In particular, the disclosed catalytic article includes a substrate having a first and a second material disposed thereon, wherein the first material includes a selective catalytic reduction (SCR) catalyst composition and the second material includes a nitrogen oxides (NOx) absorber composition, wherein the NOx absorber composition does not substantially oxidize ammonia, and wherein the catalytic article is effective to abate NOx from an engine exhaust gas stream. Emission treatment systems for treating an exhaust gas including a catalytic article of the invention are provided, particularly systems that include an injector adapted for the addition of ammonia to the exhaust gas stream located upstream of the catalytic article.
Low temperature NOx reduction using H.SUB.2.-SCR for diesel vehicles
Disclosed herein are emission treatment systems, articles, and methods for selectively reducing NOx compounds. The systems include a hydrogen generator, a hydrogen selective catalytic reduction (H.sub.2-SCR) article, and one or more of a diesel oxidation catalyst (DOC) and/or a lean NOx trap (LNT) and/or a low temperature NOx adsorber (LTNA). Certain articles may comprise a zone coated substrate and/or a layered coated substrate and/or an intermingled coated substrate of one or more of the H.sub.2-SCR and/or DOC and/or LNT and/or LTNA catalytic compositions.
Integrated catalyst system for stoichiometric-burn natural gas vehicles and preparation method therefor
Disclosed in the present invention is an integrated catalyst system for stoichiometric-burn natural gas vehicles, the catalyst system consisting of a three-way catalyst, a molecular sieve catalyst, and a base body, the three-way catalyst and the molecular sieve catalyst being coated on a surface of the base body. In the integrated three-way catalyst and molecular sieve catalyst system of the present invention, at the same time that pollutants such as CO, HC, and NO.sub.x in the exhaust of stoichiometric-burn natural gas vehicles are processed, the produced byproduct NH.sub.3 can also be processed, and the conversion rates of CO, HC, NO.sub.x, and NH.sub.3 are high.
Method and apparatus for removing NOx and N2O from a gas
Method for reducing the content of nitrogen oxides NOx and nitrous oxide N2O in an input gas, comprising the steps of: treating said gas with a first amount of a NOx reducing agent in a first de-NOx catalytic bed; treating the effluent of said first de-NOx catalytic bed in at least one de-N2O catalytic bed for removal of N2O; treating the effluent of said at least one de-N2O catalytic bed with a second amount of a NOx reducing agent in a second de-NOx catalytic bed.
Selective catalytic reduction articles and systems
The present disclosure relates to copper-containing molecular sieve catalysts that are highly suitable for the treatment of exhaust containing NOx pollutants. The copper-containing molecular sieve catalysts contain ion-exchanged copper as Cu.sup.+2 and Cu(OH).sup.+1, and DRIFT spectroscopy of the catalyst exhibits perturbed T-O-T vibrational peaks corresponding to the Cu.sup.+2 and Cu(OH).sup.+1. In spectra taken of the catalytic materials, a ratio of the Cu.sup.+2 to the Cu(OH).sup.+1 peak integration areas preferably can be ≥1. The copper-containing molecular sieve catalysts are aging stable such that the peak integration area percentage of the Cu.sup.+2 peak (area Cu.sup.+2/(area Cu.sup.+2+area Cu(OH).sup.+1)) increases by ≤20% upon aging at 800° C. for 16 hours in the presence of 10% H.sub.2O/air, compared to the fresh state.
METHOD OF PREPARING SCR CATALYST AND SCR CATALYST PREPARED THEREBY
The present disclosure provides a method of preparing a SCR (Selective Catalytic Reduction) catalyst including preparing a synthetic mother liquid that includes a source of silica and alumina including zeolite A and silica, a structure-inducing material, a complexing material, and a solvent, reacting the synthetic mother liquid to prepare CHA zeolite, and ion-exchanging the prepared CHA zeolite with a transition metal.
Cu—P co-supported zeolite, and selective catalytic reduction catalyst and catalyst for exhaust gas using same
Provided are a high-performance Cu—P co-supported zeolite and the like having excellent thermal endurance and catalyst performance. A Cu—P co-supported zeolite comprising at least a small pore size zeolite, and an extra-backbone copper atom and an extra-backbone phosphorus atom supported on the small pore size zeolite, wherein a silica-alumina ratio (SiO.sub.2/Al.sub.2O.sub.3) is 7 or more and 20 or less, a ratio of the copper atom to a T atom (Cu/T) is 0.005 or more and 0.060 or less, a ratio of the phosphorus atom to the T atom (P/T) is 0.005 or more and 0.060 or less, and a ratio of the phosphorus atom to the copper atom (P/Cu) is 0.1 or more and 3 or less.