Three-way catalyst
阅读说明：本技术 三元催化剂 (Three-way catalyst ) 是由 R·J·安德森 J·G·努南 C·M·艾丽斯 G·S·桑 于 2019-09-05 设计创作，主要内容包括：本发明涉及一种催化剂,该催化剂包括在基材端部a和b之间延伸的长度(L)的载体基材以及三个洗涂层区A、B和C,其中洗涂层区A包含一种或多种第一铂族金属并且从基材端部a开始在长度(L)的一部分上延伸,洗涂层区C包含一种或多种第一铂族金属并且从基材端部b开始在长度(L)的一部分上延伸,并且洗涂层区B包含与洗涂层区A相同的组分以及另外的一种或多种第二铂族金属并且在洗涂层区A和C之间延伸,其中L＝L-A+L-B+L-C,其中L-A是洗涂层区A的长度,L-B是基材长度B的长度,并且L-C是基材长度C的长度。(The invention relates to a catalyst comprising a support substrate of length (L) extending between substrate ends a and B and three washcoat zones A, B and C, wherein washcoat zone a comprises one or more first platinum group metals and extends over a portion of length (L) from substrate end a, washcoat zone C comprises one or more first platinum group metals and extends over a portion of length (L) from substrate end B, and washcoat zone B comprises the same components as washcoat zone a and one more additional washcoat zonesOne or more second platinum group metals and extending between washcoat regions a and C, wherein L ═ L A +L B +L C Wherein L is A Is the length of the washcoat zone A, L B Is the length of the substrate length B, and L C Is the length of the substrate length C.)
1. A catalyst comprising a carrier substrate of length L extending between substrate ends a and b and three washcoat zones A, B and C, wherein
Washcoat zone a comprising one or more first platinum group metals and extending over a portion of the length L from substrate end a,
the washcoat zone C comprises one or more first platinum group metals and extends over a portion of the length L from the substrate end b, and
washcoat zone B contains the same components as washcoat zone a and additionally one or more second platinum group metals and extends between washcoat zones a and C, where L ═ LA+LB+LCWherein L isAIs the length of the washcoat zone A, LBIs the length of the washcoat zone B, and LCIs the length of the washcoat zone C.
2. The catalyst of claim 1, wherein the first platinum group metal and the second platinum group metal are the same or different.
3. The catalyst of claim 1 and/or 2, wherein the first platinum group metal is platinum, palladium and/or rhodium and the second platinum group metal is platinum, palladium or rhodium.
4. The catalyst of one or more of claims 1 to 3, wherein the first platinum group metal is palladium and rhodium and the second platinum group metal is palladium.
5. The catalyst of one or more of claims 1 to 3, wherein the first platinum group metal is palladium and rhodium and the second platinum group metal is rhodium.
6. The catalyst of one or more of claims 1 to 3, wherein the first platinum group metal is palladium and rhodium and the second platinum group metal is platinum.
7. The catalyst according to one or more of claims 1 to 6, wherein
The washcoat zones A all being comprised in said length LATwo washcoat zones A1 and A2 extending above, wherein washcoat zone A1 comprises one or more first platinum group metals and washcoat zone A2 comprises one or more first platinum group metals different from the one or more first platinum group metals of washcoat zone A1,
the washcoat zones C all being comprised in said length LCTwo washcoat zones C1 and C2 extending above, wherein washcoat zone C1 comprises one or more first platinum group metals and washcoat zone C2 comprises one or more first platinum group metals different from the one or more first platinum group metals of washcoat zone C1, and
the washcoat zones B all being comprised in said length LBTwo washcoat zones B1 and B2 extending above, wherein washcoat zone B1 comprises the same components as washcoat zone a1 and washcoat zone B2 comprises the same components as washcoat zone a2, and wherein washcoat zones B1 and B2 comprise one or more additional second washcoat zonesA platinum group metal.
8. The catalyst of claim 7, wherein the first platinum group metal in washcoat zone A1 is palladium and/or rhodium and the first platinum group metal in washcoat zone A2 is rhodium.
9. The catalyst of claim 7, wherein the first platinum group metal in washcoat zone a1 is palladium and rhodium and the weight ratio Pd: Rh is 10:1 to 1: 10.
10. The catalyst according to one or more of claims 1 to 9, wherein the first platinum group metal and the second platinum group metal are supported on a support material independently of each other.
11. The catalyst of claim 10, wherein the support material is selected from the group consisting of: alumina, silica, magnesia, titania, zirconia, ceria, mixtures comprising at least one of these materials, and mixed oxides comprising at least one of these materials.
12. The catalyst of one or more of claims 1 to 11, wherein washcoat zone a extends over 15% to 50% of the length L of the carrier substrate, washcoat zone B extends over 7% to 30% of the length L of the carrier substrate, and washcoat zone C extends over 20% to 78% of the length L of the carrier substrate.
13. The catalyst according to one or more of claims 1 to 12, wherein the support substrate of the length L is a flow-through substrate or a filter substrate.
14. A process for the manufacture of the catalyst according to one or more of claims 1 to 13 by a four-step process, the process comprising:
coating the carrier substrate with a coating suspension (washcoat) which contains the components of the washcoat zone A over the entire length L of the carrier substrate,
at said length LAA hydrophobic masking zone extending from the end a of the substrate is applied,
immersing the coated carrier substrate in an aqueous solution containing the water-soluble compound of the second platinum group metal, starting from the substrate end a, up to the length LA+LBSo as to form a washcoat zone B, and
drying and heating the coated carrier substrate to remove the masked regions.
15. Catalyst system comprising a catalyst according to one or more of claims 1 to 14 and a further three-way catalyst, a gasoline particulate filter, an HC trap and/or a NOx trap.
16. The catalyst system according to claim 15, wherein the substrate end b of the catalyst according to one or more of claims 1 to 11 is followed by a conventional three-way catalyst.
17. The catalyst system according to claim 15, wherein the substrate end b of the catalyst according to one or more of claims 1 to 11 follows a conventional three-way catalyst.
18. Method for treating an exhaust gas of a combustion engine, wherein the exhaust gas is passed over a catalyst according to one or more of claims 1 to 13, wherein the exhaust gas enters the catalyst at substrate end a and leaves the catalyst at substrate end b.
19. The method according to claim 18, wherein the catalyst according to one or more of claims 1 to 13 is arranged in a tightly coupled position.
20. Method for treating the exhaust gases of a lean-burn engine, characterized in that the exhaust gases pass through a catalyst according to one or more of claims 1 to 13, wherein the exhaust gases enter the catalyst at substrate end a and leave the catalyst at substrate end b.