Nitrous oxide removal catalysts for exhaust systems

Patent metadata

Field	Value
Publication number	US-2022010714-A1
Application number	US-202117483135-A
Country	US
Kind code	A1
Filing date	Sep 23, 2021
Priority date	Dec 8, 2014
Publication date	Jan 13, 2022
Grant date	—

Abstract

A nitrous oxide (N2O) removal catalyst composite is provided, comprising a N2O removal catalytic material on a substrate, the catalytic material comprising a rhodium (Rh) component supported on a ceria-based support, wherein the catalyst composite has a H2-consumption peak of about 100° C. or less as measured by hydrogen temperature-programmed reduction (H2-TPR). Methods of making and using the same are also provided.

First claim

1 - 21 . (canceled)

22 . An emissions treatment system for treatment of an internal combustion engine exhaust stream including hydrocarbons, carbon monoxide, and nitrogen oxides, the emission treatment system comprising:
an exhaust conduit in fluid communication with the internal combustion engine via an exhaust manifold; a treatment catalyst; and the N 2 O removal catalyst composite comprising a N 2 O removal catalytic material on a substrate, the catalytic material comprising a rhodium (Rh) component supported on a ceria-based support, wherein the catalytic material has a H 2 -consumption peak of about 100° C. or less as measured by hydrogen temperature-programmed reduction (H 2 -TPR) and is effective to decompose at least a portion of nitrous oxide (N 2 O) in the exhaust stream to nitrogen (N 2 ) and oxygen (O 2 ) or to reduce at least a portion of the N 2 O to N 2 and water, N 2 and carbon dioxide (CO 2 ), or N 2 , water, and CO 2 under conditions of the exhaust stream.

23 . The emissions treatment system of claim 22 , wherein the treatment catalyst comprises a precious metal on a high surface area refractory metal oxide support that is effective to oxidize hydrocarbons and/or carbon monoxide under conditions of the exhaust stream.

24 . The emissions treatment system of claim 23 , wherein the treatment catalyst comprises a nitrogen oxides treatment catalyst selected from the group consisting of a three-way conversion (TWC) catalyst, a lean NOx trap (LNT), and a Selective Catalytic Reduction (SCR) catalyst.

25 . The emissions treatment system of claim 24 , wherein the N 2 O removal catalyst composite is located downstream of the nitrogen oxides treatment catalyst.

26 . The emissions treatment system of claim 24 , wherein the system is zoned and the nitrogen oxides treatment catalyst is in a front, upstream zone and the N 2 O removal catalyst composite is in a back, downstream zone.

27 . The emissions treatment system of claim 24 , wherein the system is layered and the nitrogen oxides treatment catalyst is in an outer layer and the N 2 O removal catalytic material of the catalyst composite is in an inner layer.

28 . The emissions treatment system of claim 24 , wherein the system is layered and the nitrogen oxides treatment catalyst is in an inner layer and the N 2 O removal catalytic material of the N 2 O catalyst composite is in an outer layer.

29 . A method for treating exhaust gases comprising contacting a gaseous stream comprising hydrocarbons, carbon monoxide, and nitrogen oxides with the N 2 O removal catalyst composite comprising a N 2 O removal catalytic material on a substrate, the catalytic material comprising a rhodium (Rh) component supported on a ceria-based support, wherein the catalytic material has a H 2 -consumption peak of about 100° C. or less as measured by hydrogen temperature-programmed reduction (H 2 -TPR) and is effective to decompose at least a portion of nitrous oxide (N 2 O) in the exhaust stream to nitrogen (N 2 ) and oxygen (O 2 ) or to reduce at least a portion of the N 2 O to N 2 and water, N 2 and carbon dioxide (COO, or N 2 , water, and CO 2 under conditions of the exhaust stream.

30 . The method of claim 29 , wherein N 2 O removal activity of the catalytic material after aging at 750° C. for 20 hours with 10 weight % water is higher than N 2 O removal activity of fresh catalytic material.

31 - 34 . (canceled)

Assignees

• Basf Corp

Inventors

• Li Yuejin
• Zheng Xiaolai
• Roth Stanley
• Gerlach Olga
• Sundermann Andreas

Classifications

• B01J35/40

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

• B01J35/45

  Nanoparticles · CPC title

• B01J35/77

  Compounds characterised by their crystallite size · CPC title

• B01J37/0244 Primary

  Coatings comprising several layers · CPC title

• B01J2235/15

  X-ray diffraction · CPC title