Three-way catalytic converter using nanoparticles
The present disclosure relates to a substrate comprising nanomaterials for treatment of gases, washcoats for use in preparing such a substrate, and methods of preparation of the nanomaterials and the substrate comprising the nanomaterials. More specifically, the present disclosure relates to a substrate comprising nanomaterial for three-way catalytic converters for treatment of exhaust gases.
1. A method of forming a coated substrate, the method comprising:
a) coating a substrate with a washcoat composition comprising oxidative catalytically active particles; wherein the oxidative catalytically active particles comprise oxidative composite nanoparticles bonded to micron-sized carrier particles where the micron-sized carrier particles comprise metal oxide, and the oxidative composite nanoparticles comprise a first support nanoparticle comprising metal oxide and one or more oxidative catalyst nanoparticles comprising a first platinum group metal; and
b) coating the substrate with a washcoat composition comprising reductive catalytically active particles; wherein the reductive catalytically active particles comprise reductive composite nanoparticles bonded to micron-sized carrier particles where the micron-sized carrier particles comprise metal oxide, and the reductive composite nanoparticles comprise a second support nanoparticle comprising metal oxide and one or more reductive catalyst nanoparticles comprising a second platinum group metal.
2. The method of claim 1 , wherein the oxidative catalyst nanoparticles comprise palladium.
3. The method of claim 1 , wherein the oxidative catalyst nanoparticles comprise platinum.
4. The method of claim 1 , wherein the oxidative catalyst nanoparticles comprise a mixture of platinum and palladium.
5. The method of claim 1 , wherein the first support nanoparticle comprises aluminum oxide.
6. The method of claim 1 , wherein the micron-sized carrier particles of the oxidative catalytically active particles comprise aluminum oxide.
7. The method of claim 1 , wherein the reductive catalyst nanoparticles comprise rhodium.
8. The method of claim 1 , wherein the micron-sized carrier particles of the reductive catalytically active particles comprise cerium zirconium oxide.
9. The method of claim 1 , wherein either or both washcoat layers further comprise an oxygen storage component.
10. The method of claim 9 , wherein the oxygen storage component comprises cerium zirconium oxide or cerium oxide.
11. The method of claim 1 , further comprising drying and calcining the substrate after each coating.
12. The method of claim 1 , wherein the washcoat layers further comprise boehmite.
13. A method of forming a coated substrate, the method comprising:
a) coating a substrate with a washcoat composition comprising oxidative catalytically active particles and reductive catalytically active particles;
wherein the oxidative catalytically active particles comprise oxidative composite nanoparticles bonded to micron-sized carrier particles where the micron-sized carrier particles comprise metal oxide, and the oxidative composite nanoparticles comprise a first support nanoparticle comprising metal oxide and one or more oxidative catalyst nanoparticles comprising a first platinum group metal; and
the reductive catalytically active particles comprise reductive composite nanoparticles bonded to micron-sized carrier particles where the micron-sized carrier particles comprise metal oxide, and the reductive composite nanoparticles comprise a second support nanoparticle comprising metal oxide and one or more reductive catalyst nanoparticles comprising a second platinum group metal.
14. The method of claim 13 , wherein the oxidative catalyst nanoparticles comprise palladium.
15. The method of claim 13 , wherein the oxidative catalyst nanoparticles comprise platinum.
16. The method of claim 13 , wherein the oxidative catalyst nanoparticles comprise a mixture of platinum and palladium.
17. The method of claim 13 , wherein the first support nanoparticle comprises aluminum oxide.
18. The method of claim 13 , wherein the micron-sized carrier particles of the oxidative catalytically active particles comprise aluminum oxide.
19. The method of claim 13 , wherein the reductive catalyst nanoparticles comprise rhodium.
20. The method of claim 13 , wherein the micron-sized carrier particles of the reductive catalytically active particles comprise cerium zirconium oxide.
21. The method of claim 13 , wherein the washcoat layer further comprises an oxygen storage component.
22. The method of claim 21 , wherein the oxygen storage component comprises cerium zirconium oxide or cerium oxide.
23. The method of claim 13 , further comprising drying and calcining the substrate after the coating.
24. The method of claim 13 , wherein the washcoat layer further comprises boehmite.