Methods and processes of coating zero-PGM catalysts including with Cu, Mn, Fe for TWC applications

• US 9,610,570 B2
• Filed: 10/31/2014
• Issued: 04/04/2017
• Est. Priority Date: 03/22/2013
• Status: Expired due to Fees

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: Clean Diesel Technologies, Inc.
• Inventors: Nazarpoor, Zahra, Golden, Stephen J.
• Primary Examiner(s): BERNS, DANIEL J
• Application Number:
  US14/530,373
• Publication Number:
  US 20150105247A1
• Time in Patent Office: 886 Days
• Field of Search: None
• CPC Class Codes: B01D 2255/207 Transition metals
• CPC Class Codes: B01D 2255/20715 Zirconium
• CPC Class Codes: B01D 2255/2073 Manganese
• CPC Class Codes: B01D 2255/20761 Copper
• CPC Class Codes: B01D 2255/405 Spinels
• CPC Class Codes: B01D 2255/65 Catalysts not containing noble metals
• CPC Class Codes: B01D 53/945 characterised by a specific catalyst
• CPC Class Codes: B01J 23/20 Vanadium, niobium or tantalum
• CPC Class Codes: B01J 23/8892 Manganese
• CPC Class Codes: B01J 2523/00 Constitutive chemical elements of heterogeneous catalysts
• CPC Class Codes: B01J 2523/17 Copper
• CPC Class Codes: B01J 2523/72 Manganese
• CPC Class Codes: B01J 2523/842 Iron
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y10S 502/52712 Plural layers on a support, each layer having a distinct function

Abstract

Variations of coating processes of Cu—Mn—Fe ZPGM catalyst materials for TWC applications are disclosed. The disclosed coating processes for Cu—Mn—Fe spinel materials are enabled in the preparation ZPGM catalyst samples according to a plurality of catalyst configurations, which may include an alumina only washcoat layer coated on a suitable ceramic substrate, and an overcoat layer with or without an impregnation layer, including Cu—Mn—Fe spinel and doped Zirconia support oxide, prepared according to variations of disclosed coating processes. Activity measurements are considered under variety of lean condition to rich condition to analyze the influence of disclosed coating processes on TWC performance of ZPGM catalysts for a plurality of TWC applications. Different coating processes may substantially increase thermal stability and TWC activity, providing improved levels of NO_x conversion that may lead to cost effective manufacturing solutions for ZPGM-TWC systems.

Claims

1. A process for making a catalytic system, comprising:

providing a substrate;

applying a washcoat to said substrate, wherein the substrate comprises alumina;

applying an overcoat to said washcoat, said overcoat comprising at least one support oxide comprising doped ZrO₂;

applying to said overcoat at least one layer of Cu—

Mn spinel; and

wherein the catalytic system is free of platinum group metals; and

wherein the doped ZrO₂comprises Nb₂O₅—

ZrO₂.

2. The process of claim 1, wherein the Cu—

Mn spinel has a general formula of Cu_xMn_1-xFe₂O₄, where x is less than 0.9 and greater than 0.1.

3. The process of claim 2, wherein x is 0.5.

4. The process of claim 3;

wherein the catalytic system'"'"'s conversion of NO_x is greater than 49%.

5. The process of claim 1, wherein the Cu—

Mn spinel is impregnated.

6. The process of claim 5;

wherein the catalytic system'"'"'s conversion of NO_x is greater than 89%.

7. The process of claim 1, wherein the catalytic system'"'"'s HC T₅₀ is less than or equal to 61°

C.

8. The process of claim 1, wherein the catalytic system'"'"'s NO_xT₅₀ is less than or equal to 55°

C.

9. The process of claim 1, wherein the substrate comprises ceramics.

10. The process of claim 1, wherein the catalytic system'"'"'s conversion of NO_x increases with an increasing amount of Cu—

Mn spinel.

11. The process of claim 1, wherein the catalytic system'"'"'s NO/CO cross over increases with an increasing amount of Cu—

Mn spinel.

12. The process of claim 1, wherein the catalytic system'"'"'s catalytic performance under lean conditions increases with an increasing amount of Cu—

Mn spinel.

13. The process of claim 1, wherein engine performance under lean conditions increases with an increasing amount of Cu—

Mn spinel.