Performance enhancement of a catalyst via exhaust gas hydrogen enrichment

Patent metadata

Field	Value
Publication number	US-2024287926-A1
Application number	US-202118024833-A
Country	US
Kind code	A1
Filing date	Sep 7, 2021
Priority date	Sep 8, 2020
Publication date	Aug 29, 2024
Grant date	—

Abstract

The disclosure provides a system for treating an exhaust gas stream from a gasoline engine. The system is configured to introduce controlled quantities of hydrogen gas into the exhaust gas stream upstream of a catalyst article during a cold-start period. Further provided are related methods of treating such exhaust streams. Such systems and methods are useful in reducing a level of one or more of hydrocarbons, carbon monoxide, and nitrogen oxide in a gaseous exhaust stream from a gasoline engine.

First claim

1 . A system for treating an exhaust gas stream from a gasoline engine, the system comprising:
a catalyst article downstream of and in fluid communication with the gasoline engine; a source of hydrogen gas (H 2 ); a feedback sensor located upstream from the catalyst article and in contact with the exhaust gas stream; and a control unit in communication with the feedback sensor; wherein the system is configured to introduce H 2 from the H 2 source into the exhaust gas stream upstream of the catalyst article during a cold-start period, and wherein the feedback sensor is configured to provide H 2 in the exhaust gas stream by modulating the H 2 introduction.

2 . The system of claim 1 , wherein the catalyst article is chosen from a three-way conversion (TWC) catalyst article, a four-way conversion catalyst article, a selective catalytic reduction (SCR) catalyst article, a direct oxidation catalyst article, an ammonia oxidation (AMOx) catalyst article, and a catalyzed soot filter (CSF) article or a combination thereof.

3 . The system of claim 1 , wherein the catalyst article comprises a substrate, a first catalyst layer disposed on the substrate, and a second catalyst layer disposed on the first catalyst layer, wherein:
the first catalyst layer comprises a first palladium component, a first refractory metal oxide support, and a first oxygen storage component, wherein at least a portion of the first palladium component is impregnated on the first refractory metal oxide support, and another portion of the first palladium component is impregnated on the first oxygen storage component; and the second catalyst layer comprises a second palladium component, a second refractory metal oxide support, a second oxygen storage component, a rhodium component, and a third refractory metal oxide support, wherein at least a portion of the second palladium component is impregnated on the second refractory metal oxide support, and another portion of the second palladium component is impregnated on the second oxygen storage component, and the rhodium component is impregnated on the third refractory metal oxide support.

4 . The system of claim 1 , wherein the feedback sensor comprises a wide-band oxygen sensor (UEGO) and a temperature sensor.

5 . The system of claim 1 , wherein the source of H 2 is an on-board compressed hydrogen vessel, or an on-board hydrogen generator.

6 . (canceled)

7 . The system of claim 5 , wherein the on-board hydrogen generator comprises an alcohol reformer, an ammonia decomposition apparatus, an electrolysis apparatus, a fuel reformer, an exhaust gas reformer, or a combination thereof, or an exhaust gas reformer comprising a catalytic reforming article located upstream from the catalytic article and in fluid communication with the exhaust gas stream, or comprises at least one H 2 generating component comprising a dopant comprising nanoparticles of aluminum, nanoparticles of aluminum/nickel, nanoparticles of aluminum/silica, nanoparticles of aluminum/cobalt, nanoparticles of aluminum/magnesium, nanoparticles of alumina, nanoparticles of magnesium, nanoparticles of magnesium/nickel, nanoparticles of zinc, sodium borohydride, or a combination thereof, and wherein the at least one H 2 generating component is added to a gasoline fuel prior to combustion of said fuel in the gasoline engine.

8 . (canceled)

9 . (canceled)

10 . The system of claim 1 , further comprising a H 2 injection article upstream from the catalyst article, upstream from the feedback sensor, in fluid communication with the exhaust gas stream and with the H 2 source, and in communication with the control unit; and wherein the H 2 injection article configured to introduce H 2 from the H 2 source into the exhaust gas stream upstream of the catalyst article.

11 . The system of claim 1 , wherein the system is configured to introduce H 2 from the H 2 source into the exhaust gas stream when the exhaust gas stream temperature upstream of or within the catalytic article is in a range from about 90° C. to about 190° C.

12 . The system of claim 1 , wherein, when a temperature of the exhaust gas stream upstream of or within the catalytic article is in a range from about 90° C. to about 550° C., the exhaust gas stream contains no greater than about 20 vol % of H 2 .

13 . The system of claim 1 , wherein the exhaust gas stream contains no greater than about 2 vol % of H 2 , or no greater than about 0.5 vol % of H 2 .

14 . The system of claim 1 , wherein the system is configured to introduce H 2 from the H 2 source into the exhaust gas stream to provide a Δλ value of from about −0.014 to no more negative than about −0.345 for a period of time, wherein:

Δλ
=

λ
¯

-
λ°

;

λ° is a pre-defined value; and
λ is a running average air-to-fuel ratio of the exhaust gas stream, calculated for a length of time according to the formula:

λ
¯

=

∑

i
=
1

N

⁢

λ
i

N

;

wherein (N) is the number of points comprised in this length of time, and λ i is the air-to-fuel ratio at each point.

15 . The system of claim 13 , wherein Δλ is about −0.060, or about −0.014.

16 . A method of treating an exhaust gas stream from a gasoline engine, the method comprising:
contacting the exhaust gas stream with a catalyst article located downstream of the gasoline engine and in fluid communication with the exhaust gas stream; introducing hydrogen gas (H 2 ) from a H 2 source into the exhaust gas stream upstream of the catalyst article; and controlling a concentration by volume of H 2 in the exhaust gas stream upstream from the catalyst article, wherein controlling the concentration by volume of H 2 comprises modulating the H 2 introduction.

17 . The method of claim 16 , wherein the catalyst article is chosen from a three-way conversion (TWC) catalyst article, a four-way conversion catalyst article, a selective catalytic reduction (SCR) catalyst article, a direct oxidation catalyst article, an ammonia oxidation (AMOx) catalyst article, and a catalyzed soot filter (CSF) article or a combination thereof.

18 . The method of claim 16 , wherein the catalyst article comprises a substrate, a first catalyst layer disposed on the substrate, and a second catalyst layer disposed on the first catalyst layer, wherein:
the first catalyst layer comprises a first palladium component, a first refractory metal oxide support, and a first oxygen storage component, wherein at least a portion of the first palladium component is impregnated on the first refractory

Assignees

• Basf Corp

Inventors

• Sung Shiang
• Ji Chunxin
• Ruvinskiy Pavel

Classifications

• F01N2900/0408

  using a feed-back loop · CPC title

• F01N2610/04

  the substance being hydrogen · CPC title

• F01N2560/025

  for measuring or detecting O2, e.g. lambda sensors · CPC title

• F01N2560/024

  for measuring or detecting hydrogen H2 · CPC title

• F01N2240/30

  a fuel reformer · CPC title