Perovskite catalysts and uses thereof

Patent metadata

Field	Value
Publication number	US-11179704-B2
Application number	US-201716349936-A
Country	US
Kind code	B2
Filing date	Nov 14, 2017
Priority date	Nov 14, 2016
Publication date	Nov 23, 2021
Grant date	Nov 23, 2021

Abstract

The present disclosure provides perovskite catalytic materials and catalysts comprising platinum-group metals and perovskites. These catalysts may be used as oxygen storage materials with automotive applications, such as three-way catalysts. They are also useful for water or CO2 reduction, or thermochemical energy storage.

First claim

What is claimed is:

1. A three-way catalyst consisting essentially of a platinum-group metal and a perovskite having the formula CaCo 1-x Zr x O 3-δ wherein x is a number defined by 0.02≤x≤0.98; and δ is a number defined by 0.0≤δ≤1.0.

2. The catalyst of claim 1 , wherein the platinum-group metal is Pd, Pt, Rh, Ru or a combination thereof.

3. The catalyst of claim 1 , wherein the platinum-group metal is a combination of Pd and Rh.

4. The catalyst of claim 1 , wherein the catalyst is on an Al 2 O 3 support, a titania support, a zirconia support, a ceria support, a silica support, an alumina-silica support, a zeolite support, or a carbon support.

5. The catalyst of claim 1 , wherein the catalyst is formed into a monolith honeycomb block.

6. The catalyst of claim 1 , wherein the catalyst is coated on to a ceramic monolith honeycomb block.

7. The catalyst of claim 6 , wherein the ceramic monolith honeycomb block is a cordierite compound.

8. The catalyst of claim 1 , wherein the catalyst is used to catalyze the reduction of NO x or the oxidation of CO or hydrocarbons from an internal combustion engine.

9. The catalyst of claim 8 , wherein the internal combustion engine is an automobile engine.

10. The catalyst of claim 8 , wherein the internal combustion engine is operated under stoichiometric air-to-fuel ratio conditions.

11. The catalyst of claim 8 , wherein the internal combustion engine is fueled by diesel fuel, ethanol-gasoline hybrid fuel, gasoline or natural gas.

12. The catalyst of claim 11 , wherein the ethanol-gasoline hybrid fuel is 85% ethanol 15% gasoline (E85).

13. A method for reducing emissions from an internal combustion engine which comprises contacting an exhaust stream from the internal combustion engine with a three-way catalyst comprising a platinum-group metal and a perovskite having the formula CaCo 1-x Zr x O 3-δ wherein x is a number defined by 0.02≤x≤0.98; and δ is a number defined by 0.0≤δ≤1.0.

14. The method of claim 13 , wherein the platinum-group metal is Pd, Pt, Rh, Ru or a mixture thereof.

15. An exhaust system for reducing emissions from an internal combustion engine which comprises the catalyst of claim 1 .

16. A perovskite three-way catalyst having the formula CaCo 1-x Zr x O 3-δ wherein x is a number defined by 0.02≤x≤0.98; and δ is a number defined by 0.0≤δ≤1.0.

17. The catalyst of claim 16 wherein x is a number defined by 0.2≤x≤0.8.

18. A method of preparing the perovskite three-way catalyst of claim 16 , the method comprising:
(a) dissolving salts of Ca, Co and Zr to form a homogenous gel;
(b) drying the homogenous gel; and
(c) calcining and sintering to form the perovskite three-way catalyst.

19. The method of claim 18 , wherein the calcining is at about 300° C. to about 500° C. and the sintering is at about 800° C. to about 1400° C.

20. The method of claim 18 , wherein step (a) further comprises first heating and dissolving salts of Ca, Co and Zr in citric acid and ethylene glycol to form a solution and second heating the solution to form a homogenous gel.

Assignees

• Res Triangle Inst

Inventors

• Zheng Qinghe
• Lail Marty
• Amato Kelly E

Classifications

• Y02T10/12

  Improving ICE efficiencies · CPC title

• Y02E60/36

  Hydrogen production from non-carbon containing sources, e.g. by water electrolysis · CPC title

• B01J35/57

  Honeycombs · CPC title

• B01J23/8946 Primary

  with alkali or alkaline earth metals · CPC title

• B01J2235/15

  X-ray diffraction · CPC title