EXHAUST GAS PURIFICATION CATALYST SYSTEM

Abstract

Provided is an exhaust gas purification catalyst system comprising, in the following order, from the upstream side of an exhaust gas flow: a first exhaust gas purification catalyst apparatus 100 including a metal honeycomb substrate 110 and a first catalyst coat layer 120 on the metal honeycomb substrate 110; a heater 300; and a second exhaust purification catalyst apparatus 200 including a cordierite honeycomb substrate 210 and a second catalyst coat layer 220 on the cordierite honeycomb substrate 210, wherein the first catalyst coat layer 120 contains an adsorbent 130 that can adsorb one or two or more among NOx, HC and CO, and the second catalyst coat layer 220 contains inorganic oxide particles 230 and catalyst precious metal particles 240 supported on the inorganic oxide particles 230.

Description

Claims

1-11. (canceled)

12. An exhaust gas purification catalytic system, comprising, in this order from an upstream side of an exhaust gas flow, a first exhaust gas purification catalytic device comprising a metal honeycomb substrate and a first catalytic coating layer on the metal honeycomb substrate,a heater, anda second exhaust gas purification catalytic device comprising a cordierite honeycomb substrate and a second catalytic coating layer on the cordierite honeycomb substrate, whereinthe first catalytic coating layer comprises an adsorbent capable of adsorbing one or more of NOx, HC, and CO, andthe second catalytic coating layer comprises inorganic oxide particles and catalytic noble metal particles supported by the inorganic oxide particles.

13. The exhaust gas purification catalytic system according to claim 12, wherein the heater is a heat disk.

14. The exhaust gas purification catalytic system according to claim 12, wherein the heater is fixed to an exhaust gas flow downstream end of the metal honeycomb substrate.

15. The exhaust gas purification catalytic system according to claim 12, wherein the heater is formed integrally with an exhaust gas flow downstream side of the metal honeycomb substrate.

16. The exhaust gas purification catalytic system according to claim 12, wherein the adsorbent comprises inorganic oxide particles.

17. The exhaust gas purification catalytic system according to claim 16, wherein the adsorbent comprises zeolite particles.

18. The exhaust gas purification catalytic system according to claim 17, wherein the zeolite particles include one or more selected from BEA zeolite, AEI zeolite, MFI zeolite, EMT zeolite, ERI zeolite, MOR zeolite, FER zeolite, FAU zeolite, CHA zeolite, LEV zeolite, MWW zeolite, CON zeolite, and EUO zeolite.

19. The exhaust gas purification catalytic system according to claim 12, wherein the first catalytic coating layer is a catalytic coating layer having a two-layer configuration in which a lower layer and an upper layer are laminated in this order on the substrate, whereinthe lower layer comprises an adsorbent, inorganic oxide particles other than the adsorbent, and catalytic noble metal particles, and the catalytic noble metal particles are supported by at least one of the adsorbent and the inorganic oxide particles other than the adsorbent, andthe upper layer comprises inorganic oxide particles other than the adsorbent and catalytic noble metal particles, and the catalytic noble metal particles are supported by the inorganic oxide particles other than the adsorbent.

20. The exhaust gas purification catalytic system according to claim 12, wherein in the second catalytic coating layer, a mass of the catalytic noble metal particles in an upstream half of an exhaust gas flow is greater than a mass of the catalytic noble metal particles in a downstream half of the exhaust gas flow.

21. The exhaust gas purification catalytic system according to claim 17, wherein in the second catalytic coating layer, a mass of the catalytic noble metal particles in an upstream half of an exhaust gas flow is greater than a mass of the catalytic noble metal particles in a downstream half of the exhaust gas flow.

22. The exhaust gas purification catalytic system according to claim 18, wherein in the second catalytic coating layer, a mass of the catalytic noble metal particles in an upstream half of an exhaust gas flow is greater than a mass of the catalytic noble metal particles in a downstream half of the exhaust gas flow.

23. The exhaust gas purification catalytic system according to claim 19, wherein in the second catalytic coating layer, a mass of the catalytic noble metal particles in an upstream half of an exhaust gas flow is greater than a mass of the catalytic noble metal particles in a downstream half of the exhaust gas flow.

24. The exhaust gas purification catalytic system according to claim 20, wherein in the second catalytic coating layer, a mass of the catalytic noble metal particles in the upstream half of an exhaust gas flow is more than 50% by mass and 90% by mass or less, based on a total mass of the catalytic noble metal particles in the second catalytic coating layer.

25. The exhaust gas purification catalytic system according to claim 23, wherein in the second catalytic coating layer, a mass of the catalytic noble metal particles in the upstream half of an exhaust gas flow is more than 50% by mass and 90% by mass or less, based on a total mass of the catalytic noble metal particles in the second catalytic coating layer.

26. The exhaust gas purification catalytic system according to claim 12, wherein the second catalytic coating layer is a catalytic coating layer having a two-layer configuration in which a lower layer and an upper layer are laminated in this order on the substrate, whereinthe lower layer comprises inorganic oxide particles and catalytic noble metal particles, and the catalytic noble metal particles are supported by the inorganic oxide particles, andthe upper layer comprises inorganic oxide particles and catalytic noble metal particles, and the catalytic noble metal particles are supported by the inorganic oxide particles.

27. The exhaust gas purification catalytic system according to claim 17, wherein the second catalytic coating layer is a catalytic coating layer having a two-layer configuration in which a lower layer and an upper layer are laminated in this order on the substrate, whereinthe lower layer comprises inorganic oxide particles and catalytic noble metal particles, and the catalytic noble metal particles are supported by the inorganic oxide particles, andthe upper layer comprises inorganic oxide particles and catalytic noble metal particles, and the catalytic noble metal particles are supported by the inorganic oxide particles.

28. The exhaust gas purification catalytic system according to claim 18, wherein the second catalytic coating layer is a catalytic coating layer having a two-layer configuration in which a lower layer and an upper layer are laminated in this order on the substrate, whereinthe lower layer comprises inorganic oxide particles and catalytic noble metal particles, and the catalytic noble metal particles are supported by the inorganic oxide particles, andthe upper layer comprises inorganic oxide particles and catalytic noble metal particles, and the catalytic noble metal particles are supported by the inorganic oxide particles.

29. The exhaust gas purification catalytic system according to claim 19, wherein the second catalytic coating layer is a catalytic coating layer having a two-layer configuration in which a lower layer and an upper layer are laminated in this order on the substrate, whereinthe lower layer comprises inorganic oxide particles and catalytic noble metal particles, and the catalytic noble metal particles are supported by the inorganic oxide particles, andthe upper layer comprises inorganic oxide particles and catalytic noble metal particles, and the catalytic noble metal particles are supported by the inorganic oxide particles.

30. The exhaust gas purification catalytic system according to claim 20, wherein the second catalytic coating layer is a catalytic coating layer having a two-layer configuration in which a lower layer and an upper layer are laminated in this order on the substrate, whereinthe lower layer comprises inorganic oxide particles and catalytic noble metal particles, and the catalytic noble metal particles are supported by the inorganic oxide particles, andthe upper layer comprises inorganic oxide particles and catalytic noble metal particles, and the catalytic noble metal particles are supported by the inorganic oxide particles.

31. The exhaust gas purification catalytic system according to claim 23, wherein the second catalytic coating layer is a catalytic coating layer having a two-layer configuration in which a lower layer and an upper layer are laminated in this order on the substrate, whereinthe lower layer comprises inorganic oxide particles and catalytic noble metal particles, and the catalytic noble metal particles are supported by the inorganic oxide particles, andthe upper layer comprises inorganic oxide particles and catalytic noble metal particles, and the catalytic noble metal particles are supported by the inorganic oxide particles.