Ultrasound-assisted method for producing an scr catalytic converter

Patent metadata

Field	Value
Publication number	US-2021069691-A1
Application number	US-201916962406-A
Country	US
Kind code	A1
Filing date	Jan 16, 2019
Priority date	Jan 16, 2018
Publication date	Mar 11, 2021
Grant date	—

Abstract

The present invention relates to a method for producing automobile exhaust gas catalytic converters, to the catalytic converters as such and to the use thereof. In particular, the method comprises a step which results in a smaller particle size of the catalytically active material used.

First claim

1 . Method for producing a catalytic converter containing zeolites or zeotypes for the aftertreatment of exhaust gases of a car engine,
characterized in that prior to coating onto and/or into a support, the zeolite or zeotype is treated by means of ultrasound in such a way that the particle size thereof is largely reduced to less than 20 μm (d50).

2 . Method according to claim 1 ,
characterized in that the zeolites or zeotypes are those derived from structure types selected from the group consisting of the CHA, LEV, AEI, AFX, AFI, or KFI framework, or a mixture thereof.

3 . Method according to claim 1 ,
characterized in that the zeolite or zeotype is exchanged with iron and/or copper ions.

4 . Method according to claim 1 ,
characterized in that the coating comprises a binder selected from the group consisting of aluminum oxide, titanium dioxide, zirconium dioxide, silicon dioxide, or mixtures thereof.

5 . Method according to claim 1 ,
characterized in that the support is a wall-flow filter.

6 . Method according to claim 1 ,
characterized in that the particle size (d99) is lowered to below 7 μm.

7 . Method according to claim 1 ,
characterized in that the ultrasound is used with an amplitude of 5 to 100 μm.

8 . Method according to claim 1 ,
characterized in that the ultrasound has a frequency of 5 to 30 kHz.

9 . Method according to claim 1 ,
characterized in that the ultrasound has a power of 500 to 50000 watts.

10 . Method according to claim 1 ,
characterized in that the coating suspension is supplied to a pre-drying step after the coating of the support.

11 . Catalytic converter for the aftertreatment of exhaust gases of a car engine, produced according to claim 1 .

12 . Catalytic converter according to claim 11 ,
characterized in that the support is a wall-flow filter.

13 . Catalytic converter according to claim 12 ,
characterized in that the support has a loading with the coating of 30 to 200 g/l.

14 . A method for the after-treatment of exhaust gases of a car engine comprising placing the exhaust gases in contact with the catalytic converter according to claim 11 .

15 . Method according to claim 14 ,
characterized in that the exhaust gases are exhaust gases of a lean burning car engine.

16 . Method according to claim 14 ,
characterized in that the catalytic converter is a catalytic converter for the selective reduction of nitrogen oxides by means of ammonia.

Assignees

• Umicore Ag & Co Kg

Inventors

• Barth Benjamin
• Foerster Martin
• Schonert Morten

Classifications

• B01J35/56

  Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional [3D] monoliths · CPC title

• B01J2235/00

  Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties · CPC title

• B01J35/40

  characterised by dimensions, e.g. grain size (in a colloidal state B01J35/23; crystallite size B01J35/77) · CPC title

• Y02C20/10

  of nitrous oxide (N2O) · CPC title

• F01N2570/145

  Dinitrogen oxide · CPC title