# US 2015/0147239 A1 · ZPGM Underfloor Catalyst for Hybrid Exhaust Treatment Systems

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- Number: US 2015/0147239 A1
- Document ID: US20150147239A1
- Status: Published application
- Kind: A1
- Application number: 14/090,821
- Filed: 2013-11-26
- Published: 2015-05-28
- Earliest claimed: 2013-11-26
- Assignees: Clean Diesel Technologies Inc. (Cdti)
- Inventors: Maxime Launois; Randal L. Hatfield
- Web page: https://patentgrep.com/patent/US20150147239A1

## CPC

- B01D 53/945: {characterised by a specific catalyst}
- B01D 2255/1023: Palladium
- B01D 2255/1025: Rhodium
- B01D 2255/2065: Cerium
- B01D 2255/2066: Praseodymium
- B01D 2255/2068: Neodymium
- B01D 2255/20715: Zirconium
- B01D 2255/20761: Copper
- B01D 2255/9022: Two layers
- B01D 2255/908: O2-storage component incorporated in the catalyst
- Y02T 10/12: Improving ICE efficiencies
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

Hybrid PGM-ZPGM exhaust treatment systems are disclosed. The systems include a PGM close-couple catalytic converter followed by an underfloor ZPGM catalytic converter. The disclosed hybrid systems, including PGM based catalysts and zero-PGM based catalysts may replace pure PGM based exhaust treatment systems. The ZPGM catalyst compositions used may include copper and cerium as active ZPGM catalysts. The disclosed ZPGM underfloor converters may be designed to convert leaks from close-couple converters.

## Claims

### Claim 1

A catalyst system for use during an urban drive cycle, the catalyst system comprising:
at least one close-couple converter; and
at least one underfloor converter;
wherein the underfloor converter comprises a zero platinum group metal (ZPGM) catalyst system, comprising:
a substrate;
a washcoat suitable for deposition on the substrate, comprising at least one first oxygen storage material and alumina; and
an overcoat suitable for deposition on the substrate, comprising at least one second oxygen storage material and one selected from the group comprising copper oxide, ceria, alumina, and mixtures thereof.

### Claim 2 (depends on 1)

The catalyst system of claim 1, wherein the at least one first oxygen storage material comprises at least one selected from the group consisting of cerium, zirconium, and mixtures thereof.

### Claim 3 (depends on 1)

The catalyst system of claim 1, wherein the ratio of the at least one first oxygen storage material to alumina in the washcoat is 60:40.

### Claim 4 (depends on 1)

The catalyst system of claim 1, wherein the at least one second oxygen storage material comprises at least one selected from the group consisting of cerium, zirconium, and mixtures thereof.

### Claim 5 (depends on 1)

The catalyst system of claim 1, wherein the ratio of the at least one first oxygen storage material to alumina in the overcoat is 60:40.

### Claim 6 (depends on 1)

The catalyst system of claim 1, wherein the substrate is metallic.

### Claim 7 (depends on 1)

The catalyst system of claim 1, wherein the first oxygen storage material comprises cerium, zirconium, lanthanum, yttrium, lanthanides, actinides, and mixtures thereof.

### Claim 8 (depends on 1)

The catalyst system of claim 1, wherein the second oxygen storage material comprises cerium, zirconium, lanthanum, yttrium, lanthanides, actinides, and mixtures thereof.

### Claim 9 (depends on 1)

The catalyst system of claim 1, wherein the conversion of HC is at substantially the same rate as for a catalyst system containing platinum group metals.

### Claim 10 (depends on 1)

The catalyst system of claim 1, wherein the conversion of NoxC is at substantially the same rate as for a catalyst system containing platinum group metals.

### Claim 11 (depends on 1)

The catalyst system of claim 1, wherein the conversion of HC is at substantially the same rate as for a catalyst system containing platinum group metals when under Extra Urban Driving Cycle conditions.

### Claim 12 (depends on 1)

The catalyst system of claim 1, wherein the conversion of NOx is at substantially the same rate as for a catalyst system containing platinum group metals when under Extra Urban Driving Cycle conditions.

### Claim 13 (depends on 1)

The catalyst system of claim 1, wherein the close-couple converter is proximate to an exhaust manifold.

### Claim 14 (depends on 1)

The catalyst system of claim 1, wherein the at least one underfloor converter effectively converts at least a portion of unconverted exhaust from the at least one close-couple converter.