Porous ceramic body to reduce emissions

Patent metadata

Field	Value
Publication number	US-2018169634-A1
Application number	US-201615738434-A
Country	US
Kind code	A1
Filing date	Jun 28, 2016
Priority date	Jun 29, 2015
Publication date	Jun 21, 2018
Grant date	—

Abstract

A porous ceramic honeycomb body including a substrate of intersecting porous walls forming axial channels extending from a first end face to a second end face. An active portion of the walls include a zeolite catalyst disposed inside pores thereof and/or is comprised of an extruded zeolite and a three way catalyst (TWC) is disposed on wall surfaces of at least a portion of the active portion.

First claim

1 . A porous ceramic honeycomb body, comprising:
a substrate of porous walls forming channels extending from a first end face to a second end face; an in wall zeolite catalyst disposed inside pores of a first portion of the walls; and a three way catalyst (TWC) disposed on wall surfaces of the first portion of the walls.

2 . The porous ceramic honeycomb body of claim 1 , wherein the first portion of the walls extends at least partially from the first end face to the second end face.

3 . The porous ceramic honeycomb body of claim 1 , wherein the first portion of the walls is spaced apart from the first end face by a second portion of the walls, wherein the first end face is an inlet side of the porous ceramic honeycomb body.

4 . The porous ceramic honeycomb body of claim 3 , wherein the second portion of the walls is substantially free of zeolite catalyst inside pores of the walls.

5 . The porous ceramic honeycomb body of claim 3 , wherein the second portion of the walls has a lower mass than the first portion of the walls.

6 . The porous ceramic honeycomb body of claim 3 , wherein TWC is disposed on at least a portion of the second portion of the walls.

7 . The porous ceramic honeycomb body of claim 3 , wherein the first portion of the walls is spaced apart from the second end face by a third portion of the walls.

8 . (canceled)

9 . The porous ceramic honeycomb body of claim 7 , wherein the third portion of the walls is substantially free of zeolite inside pores of the walls.

10 . The porous ceramic honeycomb body of claim 7 , wherein TWC is disposed on at least a portion of the third portion of the walls.

11 . The porous ceramic honeycomb body of claim 1 , wherein the TWC comprises at least one of hydrocarbon oxidation, CO oxidation, and NOx reduction catalysts.

12 . The porous ceramic honeycomb body of claim 1 , wherein the zeolite comprises at least one of ZSM-5, beta-zeolites, mordenite, Y-zeolites, ultrastabilized Y-zeolites, aluminum phosphate zeolites, gmelinite, mazzite, offretite, ZSM-12, ZSM-18, Berryllophosphate-H, boggsite, SAPO-40, SAPO-41, combinations thereof, and mixtures thereof.

13 . (canceled)

14 . The porous ceramic honeycomb body of claim 1 , wherein the substrate porosity is greater than about 50% porosity.

15 . The porous ceramic honeycomb body of claim 1 , wherein the median pore size is about 7-10 μm.

16 . The porous ceramic honeycomb body of claim 1 , wherein and the density of the bare substrate is about 0.12-0.18 gm/cm 3 at a 600/3 geometry.

17 . The porous ceramic honeycomb body of claim 1 , wherein the zeolite is configured to adsorb hydrocarbon from an exhaust gas stream during cold start at and below a certain temperature and desorb hydrocarbon above the certain temperature, and
the TWC is configured to decompose at least a portion of the desorbed hydrocarbon in a temperature range having an upper limit above the certain temperature.

18 . The porous ceramic honeycomb body of claim 17 , wherein the certain temperature is a catalyst light-off temperature in a range from about 150° C. to about 250° C.

19 . The porous ceramic honeycomb body of claim 1 , wherein the substrate comprises cordierite, and
the porosity is less than about 50% porosity, the median pore size is about 7-10 μm, and the density of the substrate is about 0.19-0.35 gm/cm 3 at a 400/4 geometry.

20 . The porous ceramic honeycomb body of claim 1 , wherein the zeolite is configured to adsorb hydrocarbon during a slow cycle at and below a certain temperature and desorb hydrocarbon above the certain temperature, and
the TWC is configured to decompose at least a portion of the desorbed hydrocarbon in a temperature range including an upper limit above the certain temperature.

21 . A porous ceramic honeycomb body, comprising:
a substrate of porous walls forming channels extending from a first end face to a second end face; and a three way catalyst (TWC) disposed on wall surfaces of at least a portion of the walls, wherein the substrate comprises an extruded zeolite catalyst.

22 .- 28 . (canceled)

29 . An exhaust system, comprising:
a porous ceramic honeycomb body, comprising:
a substrate of porous walls forming channels extending from a first end face to a second end face;
an in wall zeolite catalyst disposed inside pores of a first portion of the walls; and
a three way catalyst (TWC) disposed on wall surfaces of at least a portion of the walls of the first portion of walls; and
a housing, comprising:
an inlet configured to accept an exhaust gas stream to be purified,
an outlet configured to emit purified exhaust gas stream, and
a chamber between the inlet and outlet configured to direct the exhaust gas stream to be purified into the first end face of the substrate, wherein the substrate is disposed in the chamber.

30 .- 32 . (canceled)

Assignees

• Corning Inc

Inventors

• Patil Mallanahouda Dyamanagouda

Classifications

• F01N3/101

  Three-way catalysts · CPC title

• B01D53/9477

  with catalysts positioned on separate bricks, e.g. exhaust systems · CPC title

• B01J35/04

  Operations & Transport · mapped topic

• B01D2255/504

  ZSM 5 zeolites · CPC title

• F01N2330/06

  Ceramic, e.g. monoliths · CPC title