Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > New nanoparticle catalyst brings fuel-cell cars closer to showroom

UW-Madison and University of Maryland researchers developed a new type of catalyst by surrounding a nanoparticle of ruthenium with one to two layers of platinum atoms. The result is a robust room-temperature catalyst that dramatically improves a key hydrogen purification reaction and leaves more hydrogen available to make energy in the fuel cell.
UW-Madison and University of Maryland researchers developed a new type of catalyst by surrounding a nanoparticle of ruthenium with one to two layers of platinum atoms. The result is a robust room-temperature catalyst that dramatically improves a key hydrogen purification reaction and leaves more hydrogen available to make energy in the fuel cell.

Abstract:
A University of Wisconsin-Madison and University of Maryland (UM) team has developed a new nanotechnology-driven chemical catalyst that paves the way for more efficient hydrogen fuel-cell vehicles.

New nanoparticle catalyst brings fuel-cell cars closer to showroom

Madison, WI | Posted on March 19th, 2008

Writing in this week's Advance Online Publication of Nature Materials, UW-Madison chemical and biological engineering Professor Manos Mavrikakis and UM chemistry and biochemistry Professor Bryan Eichhorn describe a new type of catalyst created by surrounding a nanoparticle of ruthenium (Ru) with one to two layers of platinum (Pt) atoms. The result is a robust room-temperature catalyst that dramatically improves a key hydrogen purification reaction and leaves more hydrogen available to make energy in the fuel cell.

One day, it could be common for fuel cells to create electricity by consuming hydrogen generated from renewable resources. For now, most of the world's hydrogen supply is derived from fossil fuels in a process called reforming.

An important step in this multistage process, called preferential oxidation of CO in the presence of hydrogen (PROX), uses a catalyst to purge hydrogen of carbon monoxide (CO) before it enters the fuel cell. CO presents a major obstacle to the practical application of fuel cells because it poisons the expensive platinum catalyst that runs the fuel cell reaction.

Attractive for transportation applications and as a battery replacement, proton exchange membrane fuel cells generate electricity using porous carbon electrodes containing a platinum catalyst separated by a solid polymer. Hydrogen fuel enters one side of the cell and oxygen enters on the opposite side. Platinum facilitates the production of protons from molecular hydrogen, and these protons cross the membrane to react with oxygen on the other side. The result is electricity with water and heat as byproducts.

A conventionally constructed catalyst combining ruthenium and platinum must be heated to 70 degrees Celsius or 158 degrees Fahrenheit in order to drive the PROX reaction, but the same elements combined as core-shell nanoparticles operate at room temperature. The lower the temperature at which catalyst activates the reactants and makes the products, the more energy is saved.

"We understand why it works," Mavrikakis says. "We know now the reason behind this marvelous behavior. The first reason is the core-cell nanostructure. This polymer-based method developed by my colleagues in Maryland allows the exact amount of an element, in this case platinum, to be placed exactly where you want it to be on specific seeds of ruthenium."

This very specific nano-architecture and composition can sustain significantly less CO on its surface than pure Pt would. Because the binding is weaker, Mavrikakis says fewer sites on the core-cell nanostructure are available to bind with CO than would occur with Pt alone. That leaves empty sites for oxygen to come in and react.

"The second reason is that there is a completely new reaction mechanism that makes this work so well," he says. "We call it hydrogen-assisted CO oxidation. It uses atomic hydrogen to attack molecular oxygen and make a hydroperoxy intermediate, which in turn, easily produces atomic oxygen. Then, atomic oxygen selectively attacks CO to produce CO2, leaving much more molecular hydrogen free to be fed to the fuel cell than pure Pt does."

While the breakthrough is important to the development of fuel-cell technology, the researchers say it's even more significant to catalysis in general.

First, the team, including graduate students Anand Nilekar of UW-Madison and Selim Alayoglu of Maryland, used theory rather than an experimental approach to zero in on ruthenium/platinum as the ideal core shell system.

Second, the nanoscale fabrication of ruthenium and platinum resulted in a different nano-architecture than when ruthenium and platinum are combined in bulk. For the field of catalysis, the pairing of these approaches could bridge the gap between surface science and catalysis opening new paths to novel and more energy-efficient materials discovery for a variety of industrially important chemical processes.

####

For more information, please click here

Contacts:
Terry Devitt
science
(608) 262-8282

Copyright © University of Wisconsin-Madison

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Production of Zirconium Carbide Nanoparticles at Low Temperature without Thermal Operations July 5th, 2015

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

New Biosensor Produced in Iran to Detect Effective Drugs in Cancer Treatment July 4th, 2015

Pioneering Southampton scientist awarded prestigious physics medal July 3rd, 2015

Discoveries

Production of Zirconium Carbide Nanoparticles at Low Temperature without Thermal Operations July 5th, 2015

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

New Biosensor Produced in Iran to Detect Effective Drugs in Cancer Treatment July 4th, 2015

Clues to inner atomic life from subtle light-emission shifts: Hyperfine structure of light absorption by short-lived cadmium atom isotopes reveals characteristics of the nucleus that matter for high precision detection methods July 3rd, 2015

Announcements

Production of Zirconium Carbide Nanoparticles at Low Temperature without Thermal Operations July 5th, 2015

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

New Biosensor Produced in Iran to Detect Effective Drugs in Cancer Treatment July 4th, 2015

Pioneering Southampton scientist awarded prestigious physics medal July 3rd, 2015

Energy

New technology using silver may hold key to electronics advances July 2nd, 2015

Visible Light-Sensitive Photocatalysts Used for Purification of Contaminated Water in Iran June 30th, 2015

June 29th, 2015

Making new materials with micro-explosions: ANU media release: Scientists have made exotic new materials by creating laser-induced micro-explosions in silicon, the common computer chip material June 29th, 2015

Automotive/Transportation

June 29th, 2015

Buckle up for fast ionic conduction June 16th, 2015

A protective shield for sensitive catalysts: Hydrogels block harmful oxygen June 15th, 2015

Slip sliding away: Graphene and diamonds prove a slippery combination June 10th, 2015

Fuel Cells

The Hydrogen-Fuel cell will revolutionize the economy of the world: New non-platinum and nanosized catalyst for polymer electrolyte fuel cell June 29th, 2015

X-rays and electrons join forces to map catalytic reactions in real-time: New technique combines electron microscopy and synchrotron X-rays to track chemical reactions under real operating conditions June 29th, 2015

Buckle up for fast ionic conduction June 16th, 2015

A protective shield for sensitive catalysts: Hydrogels block harmful oxygen June 15th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project