# US 2013/0156668 A1 · Catalyst for removing nitrogen oxides from the exhaust gas of diesel engines

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- Number: US 2013/0156668 A1
- Document ID: US20130156668A1
- Status: Published application
- Kind: A1
- Application number: 13/819,213
- Filed: 2011-09-08
- Published: 2013-06-20
- Earliest claimed: 2010-09-13
- Assignees: Umicore AG & Co. KG
- Inventors: Paul Spurk; Nicola Soeger; Elena Mueller; Stephan Malmberg
- Web page: https://patentgrep.com/patent/US20130156668A1

## CPC

- B01J 29/85: Silicoaluminophosphates [SAPO compounds]
- B01D 53/9418: {for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas}
- B01D 53/9422: {for removing nitrogen oxides by NOx storage or reduction by cyclic switching between lean and rich exhaust gases (LNT, NSC, NSR)}
- B01D 53/9477: {with catalysts positioned on separate bricks, e.g. exhaust systems}
- B01J 21/04: Alumina
- B01J 21/066: {Zirconium or hafnium; Oxides or hydroxides thereof}
- B01J 23/10: of rare earths
- B01J 23/63: with rare earths or actinides
- B01J 23/66: Silver or gold
- B01J 23/72: Copper
- B01J 23/8926: {Copper and noble metals}
- B01J 23/894: {with rare earths or actinides}
- B01J 23/8946: {with alkali or alkaline earth metals}
- B01J 29/072: Iron group metals or copper
- B01J 29/7215: {Zeolite Beta}
- B01J 29/723: {CHA-type, e.g. Chabazite, LZ-218}
- B01J 29/83: Aluminophosphates [APO compounds]
- B01J 35/19: {Catalysts containing parts with different compositions}
- B01J 37/0215: {Coating}
- B01J 37/0244: {Coatings comprising several layers}
- B01J 37/0246: {Coatings comprising a zeolite}
- B01J 37/0248: {Coatings comprising impregnated particles}
- B01J 37/038: {to form slurries or suspensions, e.g. a washcoat}
- F01N 3/0814: {combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts}
- F01N 3/0842: {Nitrogen oxides}
- F01N 3/2066: {Selective catalytic reduction [SCR]}
- B01D 2251/2067: Urea
- B01D 2255/1023: Palladium
- B01D 2255/2042: Barium
- B01D 2255/2047: Magnesium
- B01D 2255/2063: Lanthanum
- B01D 2255/2065: Cerium
- B01D 2255/20715: Zirconium
- B01D 2255/20761: Copper
- B01D 2255/2092: Aluminium
- B01D 2255/407: Zr-Ce mixed oxides
- B01D 2255/50: Zeolites
- B01D 2255/9022: Two layers
- B01D 2255/9032: Two zones
- B01D 2258/012: Diesel engines and lean burn gasoline engines
- F01N 2370/04: Zeolitic material
- F01N 2510/063: zeolites
- F01N 2510/0682: having a discontinuous, uneven or partially overlapping coating of catalytic material, e.g. higher amount of material upstream than downstream or vice versa
- F01N 2510/0684: having more than one coating layer, e.g. multi-layered coatings
- F01N 2610/02: the substance being ammonia or urea
- Y02T 10/12: Improving ICE efficiencies
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

The invention relates to a catalyst for removal of nitrogen oxides from the exhaust gas of diesel engines, and to a process for reducing the level of nitrogen oxides in the exhaust gas of diesel engines. The catalyst consists of a support body of length L and of a catalytically active coating which in turn may be formed from one or more material zones. The material zones comprise a copper-containing zeolite or a zeolite-like compound. The materials used include chabazite, SAPO-34, ALPO-34 and zeolite β. In addition, the material zones comprise at least one compound selected from the group consisting of barium oxide, barium hydroxide, barium carbonate, strontium oxide, strontium hydroxide, strontium carbonate, praseodymium oxide, lanthanum oxide, magnesium oxide, magnesium/aluminum mixed oxide, alkali metal oxide, alkali metal hydroxide, alkali metal carbonate and mixtures thereof. Noble metal may optionally also be present in the catalyst.

## Claims

### Claim 1

A catalyst for removal of nitrogen oxides from the exhaust gas of diesel engines, comprised of a support body of length L and of a catalytically active coating composed of one or more material zones comprising:
a zeolite or a zeolite-like compound containing 1-10% by weight of copper, based on the total weight of the zeolite or of the zeolite-like compound, the zeolite or the zeolite-like compound being selected from the group consisting of chabazite, SAPO-34, ALPO-34 and zeolite β; and
at least one compound selected from the group consisting of barium oxide, barium hydroxide, barium carbonate, strontium oxide, strontium hydroxide, strontium carbonate, praseodymium oxide, lanthanum oxide, magnesium oxide, magnesium/aluminum mixed oxide, alkali metal oxide, alkali metal hydroxide, alkali metal carbonate and mixtures thereof.

### Claim 2 (depends on 1)

The catalyst as claimed in claim 1,
wherein
the zeolite or the zeolite-like compound has an average mean pore size less than 4 Angstrom and is selected from the group consisting of chabazite, SAPO-34 and ALPO-34.

### Claim 3 (depends on 1)

The catalyst as claimed in claim 1,
wherein
the catalytically active coating additionally comprises cerium oxide and/or cerium/zirconium mixed oxide.

### Claim 4 (depends on 3)

The catalyst as claimed in claim 3,
wherein
the cerium oxide and/or cerium/zirconium mixed oxide is a support oxide for the compound selected from the group consisting of barium oxide, barium hydroxide, barium carbonate, strontium oxide, strontium hydroxide, strontium carbonate, praseodymium oxide, lanthanum oxide, magnesium oxide, magnesium/aluminum mixed oxide, alkali metal oxide, alkali metal hydroxide, alkali metal carbonate and mixtures thereof.

### Claim 5 (depends on 1)

The catalyst as claimed in claim 1,
wherein
the catalytically active coating additionally comprises one or more noble metals selected from the group consisting of platinum, palladium, rhodium, iridium, ruthenium, gold, silver and mixtures and/or alloys thereof.

### Claim 6 (depends on 1)

The catalyst as claimed in claim 1,
wherein
the catalytically active coating comprises two material zones, the first material zone comprising the zeolite or the zeolite-like compound, while the compound selected from the group consisting of barium oxide, barium hydroxide, barium carbonate, strontium oxide, strontium hydroxide, strontium carbonate, praseodymium oxide, lanthanum oxide, magnesium oxide, magnesium/aluminum mixed oxide, alkali metal oxide, alkali metal hydroxide, alkali metal carbonate and mixtures thereof is present in the second material zone.

### Claim 7 (depends on 5)

The catalyst as claimed in claim 5,
wherein
the catalytically active coating comprises two material zones, the first material zone comprising the zeolite or the zeolite-like compound, while the noble metal selected from the group consisting of platinum, palladium, rhodium, iridium, ruthenium, gold, silver and mixtures and/or alloys thereof is present in the second material zone.

### Claim 8 (depends on 6)

The catalyst as claimed in claim 6,
wherein
the second material zone has been applied directly to the support body and covers it over the entire length L thereof, while the first material zone has been applied to the second material zone and covers it completely on the exhaust gas side.

### Claim 9 (depends on 6)

The catalyst as claimed in claim 6,
wherein
the two material zones are arranged successively on the support body in flow direction of the exhaust gas, with the second material zone arranged on the inflow side and the first material zone on the outflow side.

### Claim 10 (depends on 6)

The catalyst as claimed in claim 6,
wherein
the two material zones are arranged successively on the support body in flow direction of the exhaust gas, with the first material zone arranged on the inflow side and the second material zone on the outflow side.

### Claim 11 (depends on 1)

A process for removing nitrogen oxides from the exhaust gas of diesel engines,
wherein
the exhaust gas to be cleaned has an air ratio λ greater than 1 and is passed over a catalyst as claimed in claim 1.

### Claim 12 (depends on 11)

The process as claimed in claim 11,
wherein
ammonia or a compound decomposable to ammonia is supplied as a reducing agent to the exhaust gas to be cleaned from a source independent of the engine prior to entry into the catalyst.

### Claim 13 (depends on 11)

The process as claimed in claim 11,
wherein
the exhaust gas to be cleaned is additionally passed over a catalyst which predominantly accelerates the selective catalytic reduction of nitrogen oxides with ammonia.

### Claim 14 (depends on 1)

An apparatus comprising a catalyst as claimed in claim 1 and an SCR catalyst arranged on the outflow side with respect thereto.

### Claim 15 (depends on 14)

A process for removing nitrogen oxides from the exhaust gas of diesel engines,
wherein the exhaust gas to be cleaned has an air ratio λ greater than 1 and is passed through the apparatus of claim 14.