EP3496853A1 - Filtre à particules pourvu d'un revêtement à effet scr - Google Patents

Filtre à particules pourvu d'un revêtement à effet scr

Info

Publication number
EP3496853A1
EP3496853A1 EP17748810.3A EP17748810A EP3496853A1 EP 3496853 A1 EP3496853 A1 EP 3496853A1 EP 17748810 A EP17748810 A EP 17748810A EP 3496853 A1 EP3496853 A1 EP 3496853A1
Authority
EP
European Patent Office
Prior art keywords
scr
coating
zeolite
layer
exchanged
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP17748810.3A
Other languages
German (de)
English (en)
Inventor
Anke Schuler
Katja Adelmann
Franz Dornhaus
Michael Schiffer
Stephan Eckhoff
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Umicore AG and Co KG
Original Assignee
Umicore AG and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Umicore AG and Co KG filed Critical Umicore AG and Co KG
Publication of EP3496853A1 publication Critical patent/EP3496853A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
    • F01N3/2066—Selective catalytic reduction [SCR]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/9404—Removing only nitrogen compounds
    • B01D53/9409—Nitrogen oxides
    • B01D53/9413—Processes characterised by a specific catalyst
    • B01D53/9418—Processes characterised by a specific catalyst for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65
    • B01J29/72—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 containing iron group metals, noble metals or copper
    • B01J29/723—CHA-type, e.g. Chabazite, LZ-218
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
    • B01J35/396—Distribution of the active metal ingredient
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/50—Catalysts, in general, characterised by their form or physical properties characterised by their shape or configuration
    • B01J35/56—Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/024—Multiple impregnation or coating
    • B01J37/0244—Coatings comprising several layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/024—Multiple impregnation or coating
    • B01J37/0246—Coatings comprising a zeolite
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/022—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters characterised by specially adapted filtering structure, e.g. honeycomb, mesh or fibrous
    • F01N3/0222—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters characterised by specially adapted filtering structure, e.g. honeycomb, mesh or fibrous the structure being monolithic, e.g. honeycombs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/033—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters in combination with other devices
    • F01N3/035—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters in combination with other devices with catalytic reactors, e.g. catalysed diesel particulate filters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/20—Reductants
    • B01D2251/206—Ammonium compounds
    • B01D2251/2062—Ammonia
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/50—Zeolites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/90—Physical characteristics of catalysts
    • B01D2255/902—Multilayered catalyst
    • B01D2255/9022—Two layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/90—Physical characteristics of catalysts
    • B01D2255/905—Catalysts having a gradually changing coating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/90—Physical characteristics of catalysts
    • B01D2255/915—Catalyst supported on particulate filters
    • B01D2255/9155—Wall flow filters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/01—Engine exhaust gases
    • B01D2258/012—Diesel engines and lean burn gasoline engines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2330/00—Structure of catalyst support or particle filter
    • F01N2330/06—Ceramic, e.g. monoliths
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2330/00—Structure of catalyst support or particle filter
    • F01N2330/30—Honeycomb supports characterised by their structural details
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2370/00—Selection of materials for exhaust purification
    • F01N2370/02—Selection of materials for exhaust purification used in catalytic reactors
    • F01N2370/04—Zeolitic material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Definitions

  • the present invention relates to a particulate filter with SCR active
  • Exhaust gases from motor vehicles with a predominantly lean-burn internal combustion engine contain, in addition to particulate emissions, in particular the primary emissions carbon monoxide CO, hydrocarbons HC and
  • Nitrogen oxides NOx Due to the relatively high oxygen content of up to 15 vol.%, Carbon monoxide and hydrocarbons can be made relatively harmless by oxidation, but the reduction of nitrogen oxides to nitrogen is much more difficult.
  • One known method for removing nitrogen oxides from exhaust gases in the presence of oxygen is the Selective Catalytic Reduction (SCR) process using ammonia on a suitable catalyst, the SCR catalyst. In this method, the nitrogen oxides to be removed from the exhaust gas are reacted with ammonia to nitrogen and water.
  • SCR Selective Catalytic Reduction
  • ammonia used as the reducing agent can be made available by metering in an ammonia-decomposable compound such as urea, ammonium carbamate or ammonium formate into the exhaust gas line and subsequent hydrolysis.
  • an ammonia-decomposable compound such as urea, ammonium carbamate or ammonium formate
  • Wall flow filters made of ceramic materials have proven particularly useful. These are composed of a plurality of parallel channels formed by porous walls. The channels are mutually sealed gas-tight at one of the two ends of the filter to form channels A which are open on the first side of the filter and closed on the second side of the filter, and channels B located on the first side of the filter closed and on the second side of the filter are open.
  • the exhaust gas flowing, for example, into the channels A can leave the filter only via the channels B, and must flow through the porous walls between the channels A and B for this purpose. As the exhaust passes through the wall, the particles are retained.
  • JPH01-151706 and WO2005 / 016497 suggest coating a wall-flow filter with an SCR catalyst in such a way that the latter penetrates the porous walls.
  • the porous walls of the wall flow filter are intended for this purpose
  • a wall flow filter is known, which is coated with SCR catalyst.
  • the SCR catalyst is located on the surfaces of the pores in the filter wall.
  • JP 2013-139035 A discloses a wall-flow filter coated with two washcoats, each containing iron-exchanged ⁇ -zeolites.
  • US 2010/077737 describes a system for the reduction of nitrogen oxides which comprises two different zeolite-based catalysts which differ in their reaction properties of nitrogen oxides.
  • a copper-exchanged zeolite is direct coated on the carrier substrate. This layer serves as a support for a second layer comprising an iron-exchanged zeolite.
  • the carrier substrate may be a diesel particulate filter.
  • the known SCR catalysts coated wall-flow filters have the disadvantage that their selectivity in the SCR reaction against the undesired oxidation of ammonia, especially at high
  • the object of the present invention is thus to provide wall-flow filters coated with SCR-active material which have an improved selectivity in the SCR reaction, in particular in the case of
  • the present invention relates to a particulate filter comprising a wall-flow filter and SCR-active material, wherein
  • the wall flow filter comprises channels extending in parallel between a first and a second end of the wall flow filter which are alternately gas-tightly sealed at either the first or second end and which are separated by porous walls whose pores have internal surfaces,
  • the SCR-active material is in the form of a coating on the inner surfaces of the pores of the porous walls
  • the coating has a gradient, so that the side of the coating facing the exhaust gas has a higher selectivity in the SCR reaction than the side of the coating facing the inner surfaces of the pores.
  • Wall-flow filters which can be used in accordance with the present invention are known and available on the market. They consist for example of silicon carbide, aluminum titanate or cordierite. They have uncoated state, for example, porosities of 30 to 80, especially 50 to 75%. Their average pore size when uncoated, for example, 5 to 30 microns.
  • the pores of the wall-flow filter are so-called open pores, that is to say they have a connection to the channels. Furthermore, the pores are usually interconnected. This allows, on the one hand, the slight coating of the inner pore surfaces and, on the other hand, an easy passage of the exhaust gas through the porous walls of the wall-flow filter.
  • SCR-active material is understood as meaning a material which effects the SCR reaction, ie the conversion of
  • Nitrogen oxides can catalyze with ammonia to nitrogen and water in the exhaust lean-burned combustion engines.
  • a suitable SCR active material thus has to implement nitrogen oxides effectively under the conditions prevailing in the exhaust gas, including, for example, temperatures of 200 to 750 °.
  • all known SCR catalytically active materials can be used according to the invention as the SCR-active material.
  • Examples are, for example, vanadium-containing or vanadium-free mixed oxides, as described, for example, in WO2008 / 049491 A1, WO2011 / 116907 A2 and US Pat
  • the SCR active material comprises a small pore zeolite exchanged with copper and / or iron.
  • Small-pore zeolites have a maximum ring size of eight tetrahedral atoms.
  • Well-known zeolites of this type can be used. These include naturally occurring, but preferably synthetically produced small-pore zeolites. Examples of synthetically produced small-pore zeolites include the structure types ABW, ACO, AEI, AEN, AFN, AFT, AFX, ANA, APC, APD, ATN, ATT, ATV, AWO, AWW, BIK, BRE, CAS, CDO CHA, DDR, DFT, EAB, EDI, EPI, ERI, ESV, GIS, GOO, IHW, ITE, ITW, JBW, KFI, LEV, LTA, LTJ, MER, MON, MTF, NSI, OWE, PAU, PHI, RHO, RTE, RTH, SAS, SAT, SAV, SIV, THO, TSC, UEI, UFI, VNI
  • Preferred small-pore zeolites are those which belong to the structure types AEI, CHA (chabazite), ERI (erionite), LEV (Levyne), AFX, DDR and KFI.
  • CHA CHA
  • AEI AEI
  • ERI AEI
  • LEV LEV
  • zeolite is intended to include not only aluminosilicates, but also silicoaluminophosphates and aluminophosphates, sometimes referred to as zeolite-like compounds.
  • the small pore aluminosilicate-type zeolites have a SAR of from 5 to 50, preferably from 14 to 40, more preferably between 20 and 35.
  • Suitable silicoaluminophosphates or aluminophosphates in particular also belong to the structure types AEI, CHA (chabazite), ERI
  • the zeolites mentioned are exchanged with iron and / or copper, in particular with copper.
  • the amounts of iron or copper are in particular 0.2 to 6 wt .-%, calculated as Fe 2 03 or CuO and based on the total weight of the exchanged zeolite.
  • the coating of the inner surfaces of the pores of the porous walls with SCR-active material has a gradient. This can be continuous, i. the selectivity of the SCR active material continuously decreases from the exhaust side of the coating to the side of the coating facing the interior surfaces of the pores.
  • the gradient is discontinuous.
  • the coating consists, for example, of two or more layers which differ with regard to the selectivity of the SCR-active material.
  • the outermost layer that is to say the layer facing the exhaust gas, has the highest selectivity and the innermost layer has the lowest selectivity.
  • the coating consists of two layers, wherein the layer facing the exhaust gas has a higher selectivity in the SCR reaction than the layer facing the inner surface of the pores.
  • selectivity is defined as the quotient of the conversion of NO x and the conversion of
  • the quotient X (NOX) / X (NH3) is calculated.
  • the coating with the highest quotient is inventively arranged so that it faces the exhaust gas, while the coating with the
  • the amount of coating with SCR catalytically active material is 70 to 150, in particular 90 to 130 g / L, based on the volume of the wall-flow filter. If the coating with SCR catalytically active material consists of two layers, the amount of one layer is, for example, 40 to 100 g / L and that of the other 30 to 50 g / L.
  • the small-pore zeolite of the layer facing the exhaust gas contains less than 3, preferably 0.3-2.5, particularly preferably 0.5-1.5 wt .-% Cu, calculated as CuO and based on the exchanged zeolite of this layer, while the small pore zeolite of the inner pore surface facing layer Ibis 6, preferably 2-5, more preferably 3-4.5 wt .-% Cu, calculated as CuO and based on the exchanged zeolite of this layer contains.
  • the amounts of copper in both layers are to be coordinated so that the coating facing the exhaust gas has the higher selectivity (determined as described above).
  • the layer facing the exhaust gas may also contain a small-pore zeolite which has not been exchanged with copper but is in the form of an H or NhU.
  • the layer facing the exhaust gas contains less copper calculated as CuO per unit weight washcoat than the layer facing the inner pore surface. It should be noted that the preferred amount of copper in the
  • the ratio of exchanged copper to aluminum (Cu / Al) in the zeolite the ratio of exchanged copper to aluminum (Cu / Al) in the zeolite
  • the layer facing the exhaust gas contains a small pore zeolite having a lower SiO 2 / Al 2 O 3 ratio (SAR) than the small pore zeolite contained in the layer facing the inner pore surface.
  • SAR SiO 2 / Al 2 O 3 ratio
  • the amount of coating of the layer facing the exhaust gas at 20-70g / L, preferably at 30-60g / L and the amount of coating of the inner pore surface facing layer at 50-120g / L, is preferred 70-100g / L.
  • the mass of the coating of the layer facing the exhaust gas is less than the mass of the inner pore surface
  • the chabazite of the layer facing the exhaust gas contains 1% by weight of Cu, calculated as CuO and based on the exchanged chabazite this layer, while the chabazite of the inner pore surface facing layer 3 wt .-% Cu, calculated as CuO and based on the exchanged chabazite of this layer contains.
  • Coatings are preferably present in amounts of 50% of the total coating amount.
  • the coating of SCR active material consists of two layers, each containing a copper-exchanged zeolite of the LEV type.
  • the levyne of the layer facing the exhaust gas contains 1% by weight of Cu, calculated as CuO and based on the exchanged Levyne of this layer, while the Levyne of the layer facing the inner pore surface contains 3% by weight of Cu, calculated as CuO and based on the
  • Both coatings are preferably present in amounts of 50% of the total coating amount.
  • the particle filter according to the invention achieves the stated object.
  • the contact times of the nitrogen oxides and ammonia to be reacted with the catalytically active material are particularly low in the particle filter according to the invention, at least lower than conventionally coated flow and wall flow filter substrates.
  • the reactants diffuse into the catalytically active layer and the resulting reaction products diffuse from the catalytically active layer back into the exhaust gas stream. This mechanism can take place over the entire length of the substrate.
  • Coatings are on the filter walls, the flow is turbulent, but the mechanism described above can also for Wear come. In addition, the reactants flow through the
  • catalytically active layer and the flow through the filter wall is a particularly intense contact. See, for example, EP 1 300 193 AI.
  • the exhaust gas does not flow through the catalytically active coating, nor is contact possible over the entire filter length. Rather, there is only a short contact time during the passage of the exhaust gas through the filter wall, during which the reactants and the catalytically active layer can touch. It was therefore not foreseeable that the
  • the preparation of the particulate filter according to the invention can be carried out by methods familiar to the person skilled in the art, for example by the customary dip coating method or pump and suction coating method with subsequent thermal aftertreatment (calcination and optionally reduction with forming gas or hydrogen).
  • the average particle size of the SCR catalytically active materials must be small enough to penetrate the pores of the wallflow filter.
  • the particulate filter according to the invention can be used with advantage for purifying exhaust gas from lean-burn internal combustion engines, in particular diesel engines. It removes particles from the exhaust gas and converts nitrogen oxides contained in the exhaust gas into the innocuous compounds nitrogen and water.
  • the present invention accordingly also relates to a method for
  • the reducing agent used in the process according to the invention is preferably ammonia.
  • the required ammonia can be any suitable reducing agent.
  • a particle filter for example, be formed in the exhaust system upstream of the particle filter according to the invention, for example by means of an upstream nitrogen oxide storage catalytic converter (Jean NOx trap - LNT), especially during operation under rich (rieh) exhaust conditions.
  • This method is known as "passive SCR”.
  • ammonia can also be carried in the form of aqueous urea solution in the "active SCR process", which is metered in as required via an injector upstream of the particle filter according to the invention.
  • the present invention thus also relates to an apparatus for purifying exhaust gas of lean-burn internal combustion engines, which is characterized in that it comprises a particulate filter according to the invention, and a means for providing a reducing agent.
  • the means for providing a reducing agent is thus an injector for aqueous urea solution.
  • the injector is usually fed with aqueous urea solution, which comes from an entrained reservoir, so for example a tank container.
  • the means for providing a reducing agent is usually fed with aqueous urea solution, which comes from an entrained reservoir, so for example a tank container.
  • nitrogen oxide storage catalyst which is able to form ammonia from nitrogen oxide.
  • nitrogen oxide storage catalysts are known to the person skilled in the art and comprehensively described in the literature. For example, from SAE-2001-01-3625 it is known that the SCR reaction with ammonia is faster if the nitrogen oxides are present in a 1: 1 mixture of nitrogen monoxide and nitrogen dioxide or at least approximate this ratio. Because the exhaust gas is operated by lean
  • the device according to the invention thus also comprises an oxidation catalyst.
  • an oxidation catalyst platinum on a support material is used as the oxidation catalyst.
  • Suitable carrier material for the platinum are all those skilled in the art for this purpose materials into consideration. They have a BET surface area of from 30 to 250 m 2 / g, preferably from 100 to 200 m 2 / g (determined to ISO 9277) and are in particular aluminum oxide, silicon oxide,
  • the device according to the invention is, for example, constructed so that in the flow direction of the exhaust gas first the oxidation catalyst, then the injector for aqueous urea solution and then the particle filter according to the invention are arranged.
  • a nitrogen oxide storage catalyst and then the particle filter according to the invention are arranged in the flow direction of the exhaust gas.
  • ammonia can be formed under reductive exhaust gas conditions.
  • Oxidation catalyst and injector for aqueous urea solution are dispensable in this case.
  • the invention is explained in more detail in the following examples and figures. shows a cross section through the porous wall of a particulate filter according to the invention, comprising two layers with SCR catalytically active material, wherein
  • VK2 shows the NOx conversion of K2 and VK3 (Example 2 and Comparative Examples 1 and 2) shows the NOx conversion of K2 and VK3 (Example 2 and Comparative Examples 1 and 2) shows the NOx conversion of K2 and VK3 (Example 2 and Comparative Examples 1 and 2) shows the NOx conversion of K2 and VK3 (Example 2 and Comparative Examples 1 and 2) shows the NOx conversion of K2 and VK3 (Example 2 and
  • Porosity of 65% and an average pore size of 23 pm was coated by a conventional dipping method with 60 g / L of a washcoat containing a copper-exchanged chabazite, with a
  • SAR copper-exchanged chabazite
  • the catalyst is referred to below as Kl.
  • Copper amount of 2 wt.% (Calculated as CuO and based on the exchanged chabazite) contained.
  • the mean particle size of the copper-exchanged chabazite was 1.06 pm.
  • the coated wall-flow filter was dried and calcined.
  • the catalyst is hereinafter called VK1. Comparative Example 2
  • the mean particle size of the copper-exchanged chabazite was 1.05 ⁇ . ⁇ .
  • the coated wall-flow filter was dried and calcined, b) in a second step, that coated according to a)
  • Wandschfilter also provided on the uncoated part of its length (50%) on the outlet side with a second coating.
  • the mean particle size of the copper-exchanged chabazite was 1.16 pm. Subsequently, the coated
  • Wall flow filter dried and calcined.
  • the catalyst is hereinafter called VK2.
  • the NOx turnover test consists of a test procedure, which is a
  • the maximum rate for the test procedure area 2c is determined.
  • the application of the maximum NOx rate for the various temperature points results in a job as shown in Figure 2.
  • Kl shows a significantly better NOx conversion compared to VK1 and VK2.
  • the mean particle size of the copper-exchanged chabazite was 1.43 pm.
  • the coated wall flow filter was dried, calcined at 350 ° C and annealed at 550 ° C.
  • the catalyst is hereinafter called VKB.
  • VKB A commercial wall-flow filter made of silicon carbide with a
  • the mean particle size of the copper-exchanged chabazite was 1.93 pm.
  • the coated wall flow filter was dried, calcined at 350 ° C and annealed at 550 ° C.
  • the catalyst is hereinafter called VKC. c)
  • VKB and VKC were at 800 ° C for 16 hours
  • VKC has a higher ratio of NOx and NH3 conversions than VKB.
  • VKC is to be coated on the side facing the gas and VKB on the side facing the wall flow filter.
  • the mean particle size of the copper-exchanged chabazite was 1.43 pm. Subsequently, the coated
  • the wall flow filter coated according to a) was provided with a second coating.
  • the mean particle size of the copper-exchanged chabazite was 1.93 pm.
  • the coated wall flow filter was dried, calcined at 350 ° C and annealed at 550 ° C.
  • Copper amount of 3.8 wt.% (Calculated as CuO and based on the exchanged chabazite) contained.
  • the mean particle size of the copper-exchanged chabazite was 1.61pm.
  • the catalyst is hereinafter called VK3.
  • the determination of the NOx conversion of K2 and VK3 (and of VKB and VKC) was carried out as described in Example 1. The result is shown in FIG. 3.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Combustion & Propulsion (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Biomedical Technology (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • General Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Environmental & Geological Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Catalysts (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)

Abstract

La présente invention concerne un filtre à particules qui comprend un filtre à effet wall-flow et un matériau à effet SCR, le filtre à effet wall-flow comprenant des canaux qui s'étendent de manière parallèle entre une première et une seconde extrémité du filtre à effet wall-flow, lesdits canaux sont fermés de manière étanche au gaz, de manière alternée, soit à la première, soit à la seconde extrémité et sont séparés par des parois poreuses dont les pores présentent des surfaces intérieures et le matériau à effet SCR se présente sous forme de revêtement sur les surfaces intérieures des pores des parois poreuses. Ledit filtre à particules se caractérise en ce que le revêtement présente un certain gradient, de sorte que la face du revêtement tournée vers les gaz brûlés présente une plus grande sélectivité dans la réaction SCR que la face du revêtement tournée vers les surfaces intérieures des pores. Le matériau à effet SCR est de préférence une zéolithe à pores de petite taille qui présente une taille d'ouverture de pores maximale de huit atomes tétraédriques et est remplacée par du cuivre et/ou du fer.
EP17748810.3A 2016-08-11 2017-08-11 Filtre à particules pourvu d'un revêtement à effet scr Withdrawn EP3496853A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP16183868.5A EP3281699A1 (fr) 2016-08-11 2016-08-11 Filtre à particules avec catalyseur de réduction catalytique sélective
PCT/EP2017/070401 WO2018029330A1 (fr) 2016-08-11 2017-08-11 Filtre à particules pourvu d'un revêtement à effet scr

Publications (1)

Publication Number Publication Date
EP3496853A1 true EP3496853A1 (fr) 2019-06-19

Family

ID=56799249

Family Applications (2)

Application Number Title Priority Date Filing Date
EP16183868.5A Withdrawn EP3281699A1 (fr) 2016-08-11 2016-08-11 Filtre à particules avec catalyseur de réduction catalytique sélective
EP17748810.3A Withdrawn EP3496853A1 (fr) 2016-08-11 2017-08-11 Filtre à particules pourvu d'un revêtement à effet scr

Family Applications Before (1)

Application Number Title Priority Date Filing Date
EP16183868.5A Withdrawn EP3281699A1 (fr) 2016-08-11 2016-08-11 Filtre à particules avec catalyseur de réduction catalytique sélective

Country Status (5)

Country Link
US (1) US10989089B2 (fr)
EP (2) EP3281699A1 (fr)
KR (1) KR102513661B1 (fr)
CN (1) CN109641195B (fr)
WO (1) WO2018029330A1 (fr)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11261097B2 (en) 2018-05-14 2022-03-01 Umicore Ag & Co. Kg Stable small-pore zeolites
US20210138441A1 (en) 2018-05-14 2021-05-13 Umicore Ag & Co. Kg Stable CHA Zeolites
EP3841064A1 (fr) 2018-08-24 2021-06-30 UMICORE AG & Co. KG Méthode de préparation d'un tamis moléculaire du type cha
EP3912962A1 (fr) 2020-05-18 2021-11-24 UMICORE AG & Co. KG Zéolithes chargées en cuivre ayant une forte activité de réduction catalytique (scr) de nh3
CN114308114B (zh) * 2020-09-30 2023-02-10 大连理工大学 一种脱硝催化剂及其制备方法、应用
EP4320075A1 (fr) 2021-04-09 2024-02-14 Umicore AG & Co. KG Synthèse monotope de chabazites à activation par un métal de transition

Family Cites Families (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01151706A (ja) 1987-12-08 1989-06-14 Toyota Central Res & Dev Lab Inc 可燃性微粒子と窒素酸化物を除去するための触媒及びフィルター
EP1300193A1 (fr) 2001-10-06 2003-04-09 OMG AG & Co. KG Procédé et dispositif pour la conversion des pollutants gaz eux contenus dans le gaz d'échappement des moteurs thermiques
US7229597B2 (en) 2003-08-05 2007-06-12 Basfd Catalysts Llc Catalyzed SCR filter and emission treatment system
CA2666550C (fr) 2006-10-23 2014-07-15 Umicore Ag & Co. Kg Catalyseur sans vanadium pour reduction catalytique selective et son procede de fabrication
WO2008061752A2 (fr) 2006-11-23 2008-05-29 Ixetic Mac Gmbh Arbre d'entraînement
DE502007005188D1 (de) * 2007-03-19 2010-11-11 Umicore Ag & Co Kg Doppelschichtiger Dreiweg-Katalysator
CN100588460C (zh) * 2008-02-04 2010-02-10 北京英泰世纪环境科技有限公司 一种双层贵金属活性组份催化剂及其制备方法
ATE460973T1 (de) 2008-04-11 2010-04-15 Umicore Ag & Co Kg Abgasreinigungssystem zur behandlung von motorenabgasen mittels scr-katalysator
US8225597B2 (en) * 2008-09-30 2012-07-24 Ford Global Technologies, Llc System for reducing NOx in exhaust
PL2319606T5 (pl) * 2008-11-04 2020-01-31 Umicore Ag & Co. Kg Filtr drobin zawartych w spalinach silników wysokoprężnych ze zoptymalizowanymi właściwościami ciśnienia spiętrzania
EP2335810B1 (fr) 2009-12-11 2012-08-01 Umicore AG & Co. KG Réduction catalytique sélective d'oxydes d'azote dans du gaz d'échappement de moteurs diesel
US8017097B1 (en) 2010-03-26 2011-09-13 Umicore Ag & Co. Kg ZrOx, Ce-ZrOx, Ce-Zr-REOx as host matrices for redox active cations for low temperature, hydrothermally durable and poison resistant SCR catalysts
PL2558691T3 (pl) * 2010-04-14 2017-01-31 Umicore Ag & Co. Kg Filtr cząstek stałych z powłoką redukcyjno-katalityczną o polepszonych właściwościach
CN102844112B (zh) 2010-04-20 2015-05-13 尤米科尔股份公司及两合公司 用于在废气中选择性催化还原氮氧化物的新的混合氧化物
MY163935A (en) 2010-05-05 2017-11-15 Basf Corp Catalyzed soot filter and emissions treatment systems and methods
US8722000B2 (en) 2011-03-29 2014-05-13 Basf Corporation Multi-component filters for emissions control
US9273578B2 (en) 2011-06-07 2016-03-01 Umicore Ag & Co. Kg Catalytic converter for the selective catalytic reduction of nitrogen oxides in the exhaust gas of diesel engines
US8789356B2 (en) * 2011-07-28 2014-07-29 Johnson Matthey Public Limited Company Zoned catalytic filters for treatment of exhaust gas
JP2014530097A (ja) * 2011-10-05 2014-11-17 ビーエーエスエフ ソシエタス・ヨーロピアＢａｓｆ Ｓｅ ガス流中のＮＯｘを処理するためのＣｕ−ＣＨＡ／Ｆｅ−ＢＥＡ混合ゼオライト触媒および方法
HRP20211668T1 (hr) 2011-11-22 2022-02-18 Deutz Aktiengesellschaft Postupak i uređaj za čišćenje ispušnih plinova dizel motora
CN103157520A (zh) * 2013-03-04 2013-06-19 上海云汇环保科技有限公司 一种径向梯度负载三效催化剂及其制备方法
JP5651727B2 (ja) * 2013-03-05 2015-01-14 エヌ・イーケムキャット株式会社 選択還元触媒を用いた排気ガス浄化方法
FR3011487B1 (fr) 2013-10-07 2017-07-21 Peugeot Citroen Automobiles Sa Dispositif de traitement des gaz d’echappement
US20150231620A1 (en) * 2014-02-19 2015-08-20 Ford Global Technologies, Llc IRON-ZEOLITE CHABAZITE CATALYST FOR USE IN NOx REDUCTION AND METHOD OF MAKING
RU2701529C2 (ru) * 2015-02-27 2019-09-27 Басф Корпорейшн Система обработки выхлопного газа
JP6004028B2 (ja) * 2015-03-20 2016-10-05 トヨタ自動車株式会社 排気浄化システムの故障診断装置
EP3081775B1 (fr) * 2015-04-15 2018-06-06 Toyota Jidosha Kabushiki Kaisha Appareil et méthode de purification de gaz d'échappement pour moteur à combustion interne
WO2016205509A1 (fr) 2015-06-18 2016-12-22 Johnson Matthey Public Limited Company Catalyseur de conversion d'excès d'ammoniac à faible formation de n2o
US11448110B2 (en) 2016-08-05 2022-09-20 Basf Corporation Selective catalytic reduction articles and systems
BR112019001997B1 (pt) 2016-08-05 2023-04-18 Basf Corporation Artigo de redução catalítica seletiva, sistemas de tratamento de gases de exaustão e método para tratar uma corrente de exaustão

Also Published As

Publication number Publication date
CN109641195A (zh) 2019-04-16
CN109641195B (zh) 2023-01-10
KR20190040242A (ko) 2019-04-17
WO2018029330A1 (fr) 2018-02-15
KR102513661B1 (ko) 2023-03-27
EP3281699A1 (fr) 2018-02-14
US10989089B2 (en) 2021-04-27
US20190203625A1 (en) 2019-07-04

Similar Documents

Publication Publication Date Title
WO2018029330A1 (fr) Filtre à particules pourvu d'un revêtement à effet scr
EP2718011B1 (fr) Procédé pour la réduction catalytique sélective d'oxydes d'azote dans les gaz d'échappement de moteurs diesel
EP3296009B1 (fr) Filtre à particules avec revêtement active à réduction catalytique sélective
EP3442687A1 (fr) Filtre à particules pourvu d'un revêtement à effet scr
EP2985068A1 (fr) Système catalytique pour la réduction d'oxydes d'azote
DE102008009672B4 (de) SCR-Katalysator mit Kohlenwasserstoffspeicherfunktion, dessen Verwendung und Abgasreinigungssystem und dessen Verwendung
EP3623047B1 (fr) Catalyseur de réduction d'oxydes d'azote
EP3695902B1 (fr) Catalyseur destiné à la réduction d'oxydes d'azote
EP3496852B1 (fr) Materiau scr actif
DE102017109171A1 (de) Abgassystem
DE102017109169A1 (de) Abgassystem
EP3442686A1 (fr) Catalyseur pourvu d'un revêtement à effet scr
EP3496854A1 (fr) Matériau actif scr présentant une stabilité thermique élevée
EP3449999A1 (fr) Adsorbant passif d'hémioxyde d'azote
EP3452215B1 (fr) Catalyseur actif pour la réduction catalytique sélective
EP3885040A1 (fr) Catalyseur d'oxydation d'ammoniac
WO2020141191A1 (fr) Substrat filtrant catalytiquement actif ainsi que procédé de fabrication et utilisation dudit substrat filtrant
WO2020144195A1 (fr) Adsorbeur passif d'oxyde d'azote intégrant une fonction de catalyse d'oxydation active
WO2020043578A1 (fr) Catalyseur d'accumulateur à oxyde d'azote
WO2021032702A1 (fr) Catalyseur pour réduire les émissions d'ammoniac
EP3974059A1 (fr) Procédé de fabrication d'un catalyseur destiné à l'oxydation de l'ammoniaque
EP3450016A1 (fr) Adsorbant passif d'oxyde d'azote à base de palladium et zéolithe pour le traitement de gaz d'échappement
EP3978100A1 (fr) Catalyseur d'oxydation diesel zoné contenant du bismuth
EP3791955A1 (fr) Matériau catalytique scr contenant une zéolite au cuivre et cuivre/alumine, procédé de traitement de gaz d'échappement avec ce matériau et procédé de fabrication de ce matériau
EP3885029A1 (fr) Zéolite contenant du zinc et de la platine

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20190311

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Effective date: 20200914