Ammonia production catalyst and after treatment system

Patent metadata

Field	Value
Publication number	US-2020248606-A1
Application number	US-201916263508-A
Country	US
Kind code	A1
Filing date	Jan 31, 2019
Priority date	Jan 31, 2019
Publication date	Aug 6, 2020
Grant date	—

Abstract

An after treatment system is disclosed. The after treatment system may include an exhaust pipe through which an exhaust gas flows; a three-way catalyst (TWC) mounted on the exhaust pipe and purifying HC, CO, and NOx contained in the exhaust gas, an ammonia production catalyst (APC) mounted on the exhaust pipe at a downstream of the TWC, storing NOx at a lean air/fuel ratio, and generating H2, releasing the stored NOx, and generating NH3 using the released NOx and the generated H2 at a rich air/fuel ratio, and a selective catalytic reduction (SCR) catalyst mounted on the exhaust pipe at a downstream of the APC, storing the NH3 generated in the TWC and the APC, and reducing the NOx contained in the exhaust gas using the stored NH3.

First claim

1 . An ammonia production catalyst (APC) comprising 0.4-0.9 wt % of Pt, 0.057-0.3 wt % of Pd, 0.03-0.1 wt % of Rh, 5.0-15.0 wt % of Ba, 10-30 wt % of CeO 2 , 48.7-84.513 wt % of a composite of MgO and Al 2 O 3 , and 0-5 wt % of an additive based on a total weight of the APC.

2 . The APC of claim 1 , wherein the additive comprises at least one of La, Zr, Mg, and Pr.

3 . The APC of claim 1 , wherein the composite of MgO and Al 2 O 3 includes 15-25 wt % of MgO based on a total weight of the composite of MgO and Al 2 O 3 .

4 . The APC of claim 1 , wherein a weight ratio of Pt to Pd is 3:1 to 7:1.

5 . An ammonia production catalyst (APC) comprising 0.4-0.9 wt % of Pt, 0.057-0.3 wt % of Pd, 0.03-0.1 wt % of Rh, 5.0-15.0 wt % of Ba, 10-25 wt % of CeO 2 , 48.7-79.513 wt % of a composite of MgO and Al 2 O 3 , and 0-10 wt % of an additive based on a total weight of the APC

6 . The APC of claim 5 , wherein the additive comprises at least one of La, Zr, Mg, and Pr.

7 . The APC of claim 5 , wherein the composite of MgO and Al 2 O 3 includes 15-25 wt % of MgO based on a total weight of the composite of MgO and Al 2 O 3 .

8 . The APC of claim 5 , wherein a weight ratio of Pt to Pd is 3:1 to 7:1.

9 . An after treatment system comprising:
an exhaust pipe through which an exhaust gas flows; a three-way catalyst (TWC) mounted on the exhaust pipe and purifying HC, CO, and NOx contained in the exhaust gas; an ammonia production catalyst (APC) mounted on the exhaust pipe at a downstream of the TWC, storing NOx at a lean air/fuel ratio, and generating H 2 , releasing the stored NOx, and generating NH 3 using the released NOx and the generated H 2 at a rich air/fuel ratio; and a selective catalytic reduction (SCR) catalyst mounted on the exhaust pipe at a downstream of the APC, storing the NH 3 generated in the TWC and the APC, and reducing the NOx contained in the exhaust gas using the stored NH 3 . he fastening apparatus of claim 8 , wherein the bevel ring gear is fixed to the at least one support plate.

10 . The after treatment system of claim 9 , further comprising a CO clean-up catalyst (CUC) mounted on the exhaust pipe at a downstream of the SCR catalyst and purifying the CO contained in the exhaust gas.

11 . The after treatment system of claim 10 , further comprising a particulate filter disposed between the TWC and the APC or between the APC and the SCR catalyst,
wherein the particulate filter traps particulate matter in the exhaust gas.

12 . The after treatment system of claim 9 , wherein the APC comprises Pt, Pd and CeO 2 ,
wherein a weight ratio of Pt to Pd is 3:1 to 7:1, and wherein weight ratio of the CeO 2 to a total weight of the APC is 10-30 wt %.

13 . The after treatment system of claim 9 , wherein the APC comprises 0.4-0.9 wt % of Pt, 0.057-0.3 wt % of Pd, 0.03-0.1 wt % of Rh, 5.0-15.0 wt % of Ba, 10-30 wt % of CeO 2 , 48.7-84.513 wt % of a composite of MgO and Al 2 O 3 , and 0-5 wt % of an additive based on a total weight of the APC.

14 . The after treatment system of claim 13 , wherein the additive comprises at least one of La, Zr, Mg, and Pr.

15 . The after treatment system of claim 13 , the composite of MgO and Al 2 O 3 includes 15-25 wt % of MgO based on a total weight of the composite of MgO and Al 2 O 3 .

16 . The after treatment system of claim 9 , wherein the APC comprises Pt, Pd and CeO 2 ,
wherein a weight ratio of Pt to Pd is 3:1 to 7:1, and wherein weight ratio of the CeO 2 to a total weight of the APC is 10-25 wt %.

17 . The after treatment system of claim 9 , wherein the APC comprises 0.4-0.9 wt % of Pt, 0.057-0.3 wt % of Pd, 0.03-0.1 wt % of Rh, 5.0-15.0 wt % of Ba, 10-25 wt % of CeO 2 , 48.7-79.513 wt % of a composite of MgO and Al 2 O 3 , and 0-10 wt % of an additive based on a total weight of the APC.

18 . The after treatment system of claim 17 , wherein the additive comprises at least one of La, Zr, Mg, and Pr.

19 . The after treatment system of claim 17 , the composite of MgO and Al2O3 includes 15-25 wt % of MgO based on a total weight of the composite of MgO and Al2O3.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Joo Nahm Roh
• Kim Chang Hwan
• Jung Changho

Classifications

• B01D2255/2065

  Cerium · CPC title

• B01D2255/915

  Catalyst supported on particulate filters · CPC title

• B01D2255/1021

  Platinum · CPC title

• B01J2523/824

  Palladium · CPC title

• B01D53/945

  characterised by a specific catalyst · CPC title