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 coated substrate comprising:
a first washcoat layer comprising oxidative catalytically active particles, the oxidative catalytically active particles comprising oxidative composite nanoparticles bonded to first micron-sized carrier particles, wherein the oxidative composite nanoparticles comprise a first support nanoparticle and one or more oxidative catalyst nanoparticles; and
a second washcoat layer comprising reductive catalytically active particles, the reductive catalytically active particles comprising reductive composite nanoparticles bonded to second micron-sized carrier particles, wherein the reductive composite nanoparticles comprise a second support nanoparticle and one or more reductive catalyst nanoparticles:
wherein the first washcoat layer is disposed underneath the second washcoat layer.
2 - 3 . (canceled)
4 . The coated substrate of claim 1 , wherein the oxidative catalyst nanoparticles comprise platinum, palladium, or a mixture thereof.
5 . The coated substrate of claim 4 , wherein the oxidative catalyst nanoparticles comprise palladium.
6 . The coated substrate of claim 1 , wherein the first support nanoparticles comprise aluminum oxide.
7 . The coated substrate of claim 1 , wherein the first micron-sized carrier particles comprise aluminum oxide.
8 . The coated substrate of claim 1 , wherein the first micron-sized carrier particle is pre-treated at a temperature range of about 700° C. to about 1500° C.
9 . The coated substrate of claim 1 , wherein the reductive catalyst nanoparticles comprise rhodium.
10 . The coated substrate of claim 1 , wherein the second support nanoparticles comprise cerium zirconium oxide.
11 . The coated substrate of claim 1 , wherein the second micron-sized carrier particles comprise cerium zirconium oxide.
12 . The coated substrate of claim 1 , wherein the support nanoparticles have an average diameter of 10 nm to 20 nm.
13 . The coated substrate of claim 1 , wherein the catalytic nanoparticles have an average diameter of between 1 nm and 5 nm.
14 . The coated substrate of claim 1 , further comprising an oxygen storage component.
15 . The coated substrate of claim 14 , wherein the oxygen storage component is cerium zirconium oxide or cerium oxide.
16 . The coated substrate of claim 1 , further comprising a NOx absorber component.
17 . The coated substrate of claim 16 , wherein the NOx absorber component is nano-sized BaO.
18 . The coated substrate of claim 16 , wherein the NOx absorber component is micron-sized BaO.
19 . The coated substrate of claim 1 , wherein the substrate comprises cordierite.
20 . The coated substrate of claim 1 , wherein the substrate comprises a grid array structure.
21 . The coated substrate of claim 1 , wherein:
the coated substrate has a platinum group metal loading of 4 g/l or less and a light-off temperature for carbon monoxide at least 5° C. lower than the light-off temperature of a substrate with the same platinum group metal loading deposited by wet-chemistry methods;
the coated substrate has a platinum group metal loading of 4 g/l or less and a light-off temperature for hydrocarbon at least 5° C. lower than the light-off temperature of a substrate with the same platinum group metal loading deposited by wet-chemistry methods; or
the coated substrate has a platinum group metal loading of 4 g/l or less and a light-off temperature for nitrogen oxide at least 5° C. lower than the light-off temperature of a substrate with the same platinum group metal loading deposited by wet-chemistry methods.
22 - 23 . (canceled)
24 . The coated substrate of claim 1 , wherein the coated substrate has a platinum group metal loading of about 3.0 g/l to about 4.0 g/l.
25 . The coated substrate of claim 1 , wherein said coated substrate has a platinum group metal loading of about 3.0 g/l to about 4.0 g/l, and after 125,000 miles of operation in a vehicular catalytic converter, the coated substrate has a light-off temperature for carbon monoxide at least 5° C. lower than a coated substrate prepared by depositing platinum group metals by wet chemical methods having the same platinum group metal loading after 125,000 miles of operation in a vehicular catalytic converter.
26 . The coated substrate of claim 1 , wherein a ratio of oxidative catalytically active particles to reductive catalytically active particles is between 6:1 and 40:1.
27 . A catalytic converter comprising a coated substrate of claim 1 .
28 . An exhaust treatment system comprising a conduit for exhaust gas and a catalytic converter comprising a coated substrate of claim 1 .
29 . A vehicle comprising a catalytic converter according to claim 27 .
30 . A method of treating an exhaust gas, comprising contacting the coated substrate of claim 1 with the exhaust gas.
31 . (canceled)
32 . A method of forming a coated substrate, the method comprising:
a) coating a substrate with a first washcoat composition comprising oxidative catalytically active particles wherein the oxidative catalytically active particles comprise oxidative composite nanoparticles bonded to first micron-sized carrier particles, and wherein the oxidative composite nanoparticles comprise a first support nanoparticle and one or more oxidative catalyst nanoparticles; and
b) coating the substrate with a second washcoat composition comprising reductive catalytically active particles wherein the reductive catalytically active particles comprise reductive composite nanoparticles bonded to second micron-sized carrier particles, and wherein the reductive composite nanoparticles comprise a second support nanoparticle and one or more reductive catalyst nanoparticles;
wherein the first washcoat composition is coated onto the substrate prior to the second washcoat composition.
33 - 34 . (canceled)
35 . A coated substrate comprising:
a first washcoat layer comprising oxidative catalytically active particles, the oxidative catalytically active particles comprising oxidative composite nanoparticles bonded to first micron-sized carrier particles, wherein the oxidative composite nanoparticles comprise a first support nanoparticle and one or more oxidative catalyst nanoparticles; and
a second washcoat layer comprising reductive catalytically active particles, the reductive catalytically active particles comprising reductive composite nanoparticles bonded to second micron-sized carrier particles, wherein the reductive composite nanoparticles comprise a second support nanoparticle and one or more reductive catalyst nanoparticles:
wherein the second washcoat layer is disposed underneath the first washcoat layer.
36 . The coated substrate of claim 35 , wherein the oxidative catalyst nanoparticles comprise platinum, palladium, or a mixture thereof.
37 . The coated substrate of claim 36 , wherein the oxidative catalyst nanoparticles comprise palladium.
38 . The coated substrate of claim 35 , wherein the first support nanoparticles comprise aluminum oxide.
39 . The coated substrate of claim 35 , wherein the first micron-sized carrier particles comprise aluminum oxide.
40 . The coated substrate of claim 35 , wherein the first micron-sized carrier particle is pre-treated at a temperature range of about 700° C. to about 1500° C.
41 . The coated substrate of claim 35 , wherein the reductive catalyst nanoparticles comprise rhodium.
42 . The coated substrate of claim 35 , wherein the second support nanoparticles comprise cerium zirconium oxide.
43 . The coated substrate of claim 35 , wherein the second micron-sized carrier particles comprise cerium zirconium oxide.
44 . The coated substrate of claim 35 , wherein the support nanoparticles have an average diameter of 10 nm to 20 nm.
45 . The coated substrate of claim 35 , wherein the catalytic nanoparticles have an average diameter of between 1 nm and 5 nm.
46 . The coated substrate of claim 35 , further comprising an oxygen storage component.
47 . The coated substrate of claim 46 , wherein the oxygen storage component is cerium zirconium oxide or cerium oxide.
48 . The coated substrate of claim 35 , further comprising a NOx absorber component.
49 . The coated substrate of claim 48 , wherein the NOx absorber component is nano-sized BaO.
50 . The coated substrate of claim 48 , wherein the NOx absorber component is micron-sized BaO.
51 . The coated substrate of claim 35 , wherein the substrate comprises cordierite.
52 . The coated substrate of claim 35 , wherein the substrate comprises a grid array structure.
53 . The coated substrate of claim 35 , wherein:
the coated substrate has a platinum group metal loading of 4 g/l or less and a light-off temperature for carbon monoxide at least 5° C. lower than the light-off temperature of a substrate with the same platinum group metal loading deposited by wet-chemistry methods;
the coated substrate has a platinum group metal loading of 4 g/l or less and a light-off temperature for hydrocarbon at least 5° C. lower than the light-off temperature of a substrate with the same platinum group metal loading deposited by wet-chemistry methods; or;
the coated substrate has a platinum group metal loading of 4 g/l or less and a light-off temperature for nitrogen oxide at least 5° C. lower than the light-off temperature of a substrate with the same platinum group metal loading deposited by wet-chemistry methods.
54 . The coated substrate of claim 35 , wherein the coated substrate has a platinum group metal loading of about 3.0 g/l to about 4.0 g/l.
55 . The coated substrate of claim 35 , wherein said coated substrate has a platinum group metal loading of about 3.0 g/l to about 4.0 g/l, and after 125,000 miles of operation in a vehicular catalytic converter, the coated substrate has a light-off temperature for carbon monoxide at least 5° C. lower than a coated substrate prepared by depositing platinum group metals by wet chemical methods having the same platinum group metal loading after 125,000 miles of operation in a vehicular catalytic converter.
56 . The coated substrate of claim 35 , wherein a ratio of oxidative catalytically active particles to reductive catalytically active particles is between 6:1 and 40:1.
57 . A catalytic converter comprising a coated substrate of claim 35 .
58 . An exhaust treatment system comprising a conduit for exhaust gas and a catalytic converter comprising a coated substrate of claim 35 .
59 . A vehicle comprising a catalytic converter according to claim 57 .
60 . A method of treating an exhaust gas, comprising contacting the coated substrate of claim 35 with the exhaust gas.
61 . A method of forming a coated substrate, the method comprising:
a) coating a substrate with a first washcoat composition comprising oxidative catalytically active particles, wherein the oxidative catalytically active particles comprise oxidative composite nanoparticles bonded to first micron-sized carrier particles, and wherein the oxidative composite nanoparticles comprise a first support nanoparticle and one or more oxidative catalyst nanoparticles; and
b) coating the substrate with a second washcoat composition comprising reductive catalytically active particles, wherein the reductive catalytically active particles comprise reductive composite nanoparticles bonded to second micron-sized carrier particles, and wherein the reductive composite nanoparticles comprise a second support nanoparticle and one or more reductive catalyst nanoparticles;
wherein the second washcoat composition is coated onto the substrate prior to the first washcoat composition.