Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Supported nanoparticle catalyst

Inactive Publication Date: 2005-01-13
3M INNOVATIVE PROPERTIES CO
View PDF22 Cites 57 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

It is an advantage of the present invention to provide supported catalysts that provide superior performance in electrochemical cells such as fuel cells.
to provide supported catalysts that provide superior performance in electrochemical cells such as fuel cells.

Problems solved by technology

Larger particle size reduces the available surface area and therefore results in lowered catalytic activity.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Supported nanoparticle catalyst
  • Supported nanoparticle catalyst
  • Supported nanoparticle catalyst

Examples

Experimental program
Comparison scheme
Effect test

example 1 (

30% Pt / C)

Pt nanoparticles were prepared in mixed solvent as follows: 12.5 g of H2PtCl6 solution (8 wt. % aqueous solution) was added to a 200 ml flask, followed by addition of 40 ml of ethylene glycol. After stirring at room temperature for 10 minutes, 50 ml of 0.5M NaOH (in ethylene glycol) was added to the flask. The solution was heated to 160° C. under nitrogen for 3 hours. A homogeneous, dark colloid solution was obtained.

The Pt particles were supported on carbon as follows: 0.88 g of carbon black Shaw C-55 (Chevron Texaco Corp., Houston, Tex.) and 20 ml of water were then added into the dark colloid solution. This mixture was kept stirring for about 2 weeks at room temperature. Then 20 ml of 1.9 M HNO3 was added with continued stirring. The mixture was stirred for another 30 minutes, then the solid was filtered and washed with de-ionized water 3 times. The wet cake was then re-dispersed into 150 ml of water and the dispersion was stirred overnight. After purging with hydroge...

example 2 (

30% Pt / C)

Pt nanoparticles were prepared in ethylene glycol as follows: 2.0 g of H2PtCl6.xH2O (Pt content 38-41%) was added to a 500 ml flask, followed by addition of 119 g of ethylene glycol. After stirring at room temperature for 20 minutes, a NaOH solution (2.2 g NaOH in 160 g EG) was added to the flask. The solution was then heated to 160° C. under nitrogen for 3 hours. A homogeneous dark colloid solution formed.

FIG. 1 is a transmission electron micrograph of the Pt nanoparticles of Example 2 demonstrating the small size of the Pt—Ru nanoparticles. The average size is 2.0 nm with a standard deviation of 0.5 nm.

The Pt particles were supported on carbon as follows: 1.8 g of carbon black Shaw C-55 was added to the above colloid solution and the mixture was kept stirring overnight at room temperature. 45 ml of 1.9 M HNO3 was added slowly to the suspension with continued stirring. 4 hours later, the solid was filtered and washed with de-ionized water 3 times. The solid was then re...

example 3 (

50% Pt / C)

Pt nanoparticles were prepared in ethylene glycol as in Example 2.

The Pt particles were supported on carbon as follows: 0.90 g of carbon black Shaw C-55 was added to a 400 ml jar with 20 ml of ethylene glycol. The suspension was hand-sheared for 2 minutes. Then 226 g of the dark colloid Pt suspension (Pt: 875 mg) was added to the 400 ml jar. The mixture was kept stirring overnight at room temperature. 60 ml of 1.9 M HNO3 was added to the suspension very slowly with continued stirring. The mixture was stirred overnight, then the solid was filtered and washed with de-ionized water 3 times. The solid was then re-dispersed into 350 ml water and the dispersion was kept stirring for 2 hours. The solid was then filtered and washed with copious amount of de-ionized water. The composition of wet cake was estimated as 12% Pt, 12% carbon and 76% water (49.3% Pt loading on catalyst).

FIG. 2 is a transmission electron micrograph of the carbon-supported Pt nanoparticles of Example 3 d...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
Temperatureaaaaaaaaaa
Fractionaaaaaaaaaa
Fractionaaaaaaaaaa
Login to View More

Abstract

A supported catalyst is provided comprising catalyst metal nanoparticles having an average particle size of 3.0 nm or less, or more typically 2.0 nm or less, and typically having a standard deviation of particle size of 0.5 nm or less, which are supported on support particles at a loading of 30% or more. Typical catalyst metals are selected from platinum, palladium, ruthenium, rhodium, iridium, osmium, molybdenum, tungsten, iron, nickel and tin. Typical support particles are carbon. A method of making a supported catalyst is provided comprising the steps of: a) providing a solution of metal chlorides of one or more catalyst metals in solvent system containing at least one polyalcohol, typically ethylene glycol containing less than 2% water; b) forming a colloidal suspension of unprotected catalyst metal nanoparticles by raising the pH of the solution, typically to a pH of 10 or higher, and heating said solution, typically to 125 ° C. or higher; c) adding support particles to the colloidal suspension; and d) depositing the unprotected catalyst metal nanoparticles on the support particles by lowering the pH of said suspension, typically to a pH of 6.5 or lower.

Description

FIELD OF THE INVENTION This invention relates to a supported catalyst having exceptionally small catalyst nanoparticles deposited on support particles in relatively high loading ratios, and methods of making same. BACKGROUND OF THE INVENTION Wang et al., “Preparation of Tractable Platinum, Rhodium, and Ruthenium Nanoclusters with Small Particle Size in Organic Media,”Chem. Mater., v. 12, pp. 1622-1627 (2000) and Chinese Patent App. No. CN1259395A disclose “unprotected” platinum nanoclusters and methods of their manufacture, i.e., platinum nanocluster colloids in organic solvents without protecting agents such as surfactants, polymers, or organic ligands. U.S. Pat. No. 4,629,709 discloses non-noble metal microaggregates obtained by irradiating a solution of a metal salt and an oxidizing radical scavenger with ionizing radiation. The reference discloses the use of the dispersed microaggregates as catalysts for the photoreduction of water into hydrogen. U.S. Pat. No. 4,136,059 disc...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): B01J21/18B01J35/02B01J23/42B01J23/46B01J35/00B01J37/02B01J37/03H01M4/86H01M4/88H01M4/92H01M8/10
CPCB01J21/18B01J23/42B01J23/462B01J35/0013B01J37/0203Y02E60/50B01J37/031H01M4/92H01M4/926H01M8/1004H01M2008/1095B01J37/0211Y02P70/50B01J35/23B82Y30/00
Inventor MAO, SHANE SHANHONGMAO, GUOPING
Owner 3M INNOVATIVE PROPERTIES CO
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com