Copper CHA zeolite catalysts

Patent metadata

Field	Value
Publication number	US-11529619-B2
Application number	US-202016855514-A
Country	US
Kind code	B2
Filing date	Apr 22, 2020
Priority date	Feb 27, 2007
Publication date	Dec 20, 2022
Grant date	Dec 20, 2022

Abstract

Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.

First claim

What is claimed is:

1. A catalyst article comprising a honeycomb wall-flow filter substrate having an SCR catalyst composition coated on the wall flow filter comprising a CuCHA zeolite catalyst having a mole ratio of silica to alumina greater than about 15 and an atomic ratio of copper to aluminum exceeding about 0.25, the SCR catalyst favoring reduction of nitrogen oxides and an ammonia oxidation catalyst coated on the wall flow filter, the ammonia oxidation catalyst favoring the oxidation of ammonia and comprising a CuCHA zeolite catalyst having a mole ratio of silica to alumina greater than about 15 and an atomic ratio of copper to aluminum exceeding about 0.25;
wherein the ammonia oxidation catalyst comprises a platinum group metal component;
wherein the platinum group metal component comprises Pt; and
wherein the platinum content is between 0.02% and 1.0% by weight of the catalyst, and the platinum loading is from about 0.5 g/in 3 to about 5 g/in 3 .

2. The catalyst article of claim 1 , wherein at least a portion of the wall-flow filter substrate is coated with Pt and CuCHA adapted to oxidize ammonia in the exhaust gas stream.

3. The catalyst article of claim 1 , wherein the ammonia oxidation catalyst comprises Cu-SSZ-13 and a platinum group metal.

4. The catalyst article of claim 1 , wherein the wherein the wall flow filter substrate comprises a ceramic.

5. The catalyst article of claim 4 , wherein the ceramic comprises cordierite.

6. The catalyst article of claim 5 , wherein the ceramic comprises silicon nitride.

Assignees

• Basf Corp

Inventors

• Bull Ivor
• Xue Wen-Mei
• Burk Patrick
• Boorse R Samuel
• Jaglowski William M
• Koermer Gerald Stephen
• Moini Ahmad
• Patchett Joseph A
• Dettling Joseph C
• Caudle Matthew Tyler

Classifications

• B01J37/0246

  Coatings comprising a zeolite · CPC title

• Y10T428/24149

  Honeycomb-like · CPC title

• B01J29/072

  Iron group metals or copper · CPC title

• C01B39/46

  Other types characterised by their X-ray diffraction pattern and their defined composition {(C01B39/023, C01B39/026, C01B39/06 take precedence)} · CPC title

• B01J29/068

  Noble metals · CPC title