# US 8,273,504 B2 · Method for manufacture of noble metal alloy catalysts and catalysts prepared therewith

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- Number: US 8,273,504 B2
- Document ID: US8273504B2
- Status: Granted
- Kind: B2
- Application number: 13/223,750
- Filed: 2011-09-01
- Published: 2012-03-08
- Granted: 2012-09-25
- Earliest claimed: 2004-10-29
- Assignees: Umicore AG & Co. KG
- Inventors: Dan V. Goia; Marco Lopez; Tapan Kumar Sau; Mihaela-Ortansa Jitianu
- Web page: https://patentgrep.com/patent/US8273504B2

## CPC

- B01D 53/944: {Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts (three-way-catalysts [TWC] B01D53/9445)}
- B01J 21/18: Carbon
- B01J 23/462: {Ruthenium}
- B01J 23/52: Gold
- B01J 23/8913: {Cobalt and noble metals}
- B01J 35/393: {Metal or metal oxide crystallite size}
- B01J 35/45: Nanoparticles
- B01J 37/0072: {Preparation of particles, e.g. dispersion of droplets in an oil bath}
- B01J 37/0211: {using a colloidal suspension}
- B01J 37/088: {Decomposition of a metal salt}
- B22F 9/24: starting from liquid metal compounds, e.g. solutions
- B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites
- H01M 4/921: {Alloys or mixtures with metallic elements}
- H01M 4/926: {on carbon or graphite}
- B01D 2255/1021: Platinum
- B01D 2255/1026: Ruthenium
- B01D 2255/106: Gold
- B01D 2255/20746: Cobalt
- B01D 2255/9202: Linear dimensions
- B01D 2257/502: Carbon monoxide
- B01J 23/40: of the platinum group metals
- B01J 2235/15: X-ray diffraction
- B22F 2998/00: Supplementary information concerning processes or compositions relating to powder metallurgy
- Y02E 60/50: Fuel cells
- 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)
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

The invention provides a method for manufacturing supported noble metal based alloy catalysts with a high degree of alloying and a small crystallite size. The method involves using polyol solvents as reaction medium and comprises a two-step reduction process in the presence of a support material. In the first step, the first metal (transition metal; e.g. Co, Cr, Ru) is activated by increasing the reaction temperature to 80 to 160° C. In the second step, the second metal (noble metal; e.g. Pt, Pd, Au) is added and the slurry is heated to the boiling point of the polyol solvent in a range of 160 to 300 ° C. The catalysts manufactured according to the method are used as electrocatalysts for polymer electrolyte membrane fuel cells (PEMFC), direct-methanol fuel cells (DMFC) or as gas phase catalysts for CO oxidation or exhaust gas purification.

## Claims

### Claim 1

A supported ternary platinum-cobalt-gold alloy catalyst with the atomic ratio Pt:Co=3:1,
wherein the crystallite size is less than 3 nm and the lattice constant is lower than 0.3870 nm (by XRD),
and wherein gold (Au) is present in an amount of 0.1 to 5 wt.-% based on the total weight of the catalyst.

### Claim 2 (depends on 1)

A supported ternary platinum-cobalt-gold alloy catalyst according to claim 1, wherein the concentration of platinum, cobalt and gold on the support is in the range of 1 to 90 wt.-% based on the total weight of the catalyst.

### Claim 3 (depends on 2)

A supported ternary platinum-cobalt-gold alloy catalyst according to claim 2, wherein the concentration of platinum, cobalt and gold on the support is in the range of 20 to 80 wt.-% based on the total weight of the catalyst.

### Claim 4 (depends on 1)

An electrochemical device which comprises the supported ternary platinum-cobalt-gold alloy catalyst of claim 1.

### Claim 5

A supported ternary platinum-cobalt-palladium alloy catalyst with the atomic ratio Pt:Co=3:1,
wherein the crystallite size is less than 3 nm and the lattice constant is lower than 0.3870 nm (by XRD),
and wherein palladium (Pd) is present in an amount of 0.1 to 5 wt.-% based on the total weight of the catalyst.

### Claim 6 (depends on 5)

A supported ternary platinum-cobalt-palladium alloy catalyst according to claim 5, wherein the concentration of platinum, cobalt and palladium on the support is in the range of 1 to 90 wt.-% based on the total weight of the catalyst.

### Claim 7 (depends on 6)

A supported ternary platinum-cobalt-palladium alloy catalyst according to claim 6, wherein the concentration of platinum, cobalt and palladium on the support is in the range of 20 to 80 wt.-% based on the total weight of the catalyst.

### Claim 8 (depends on 5)

An electrochemical device which comprises the supported ternary platinum-cobalt-palladium alloy catalyst of claim 5.