Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > New catalyst could boost cleaner fuel use

Younan Xia
A new catalyst based on dendritic platinum arms grown on palladium nanocrystals has been developed by WUSTL's Younan Xia and his collaborators. Tests have shown that the "bimetallic" catalyst outperforms commercial catalysts, which could enable a cost effective fuel cell technology and ultimately provide cleaner fuels worldwide.
Younan Xia
A new catalyst based on dendritic platinum arms grown on palladium nanocrystals has been developed by WUSTL's Younan Xia and his collaborators. Tests have shown that the "bimetallic" catalyst outperforms commercial catalysts, which could enable a cost effective fuel cell technology and ultimately provide cleaner fuels worldwide.

Abstract:
Material scientists at Washington University in St. Louis have developed a technique for a bimetallic fuel cell catalyst that is efficient, robust and two-to-five times more effective than commercial catalysts. The novel technique eventually will enable a cost effective fuel cell technology, which has been waiting in the wings for decades and should give a boost for cleaner use of fuels worldwide.

New catalyst could boost cleaner fuel use

St. Louis, MO | Posted on May 14th, 2009

Younan Xia, Ph.D., the James M. McKelvey Professor of Biomedical Engineering at WUSTL led a team of scientists at WUSTL and the Brookhaven National Laboratory in developing a bimetallic catalyst comprised of a palladium core or "seed" that supports dendritic platinum branches, or arms, that are fixed on the nanostructure, consisting of a nine-nanometer core and seven-nanometer platinum arms. They synthesized the catalysts by sequentially reducing precursor compounds to palladium and platinum with L-ascorbic acid (that is, Vitamin C) in an aqueous solution. The catalysts have a high surface area, invaluable for a number of applications besides in fuel cells, and are robust and stable.

Xia and his team tested how the catalysts performed in the oxygen reduction reaction process in a fuel cell, which determines how large a current will be generated in an electrochemical system similar to the cathode of a fuel cell. They found that their bimetallic nanodendrites, at room temperature, were two-and-a-half times more effective per platinum mass for this process than the state of the art commercial platinum catalyst and five times more active than the other popular commercial catalyst. At 60 degrees C (the typical operation temperature of a fuel cell), the performance almost meets the targets set by the U.S. Department of Energy.

The Department of Energy has estimated for widespread commercial success the "loading" of platinum catalysts in a fuel cell should be reduced by four times in order to slash the costs. The WUSTL technique is expected to substantially reduce the loading of platinum, making a more robust catalyst that won't have to be replaced often, and making better use of a very limited and very expensive supply of platinum in the world.

The study was published in the online journal Science.

"There are two ways to make a more effective catalyst," Xia says. "One is to control the size, making it smaller, which gives the catalyst a higher specific surface area on a mass basis. Another is to change the arrangement of atoms on the surface. We did both. You can have a square or hexagonal arrangement for the surface atoms. We chose the hexagonal lattice because people have found that it's twice as good as the square one for the oxygen reduction reaction.

"We're excited by the technique, specifically with the performance of the new catalyst."

Xia says seeded growth has emerged recently as a good technique for precisely controlling the shape and composition of metallic nanostructures prepared in solutions. And it's the only technique that allowed Xia and his collaborators to come up with their unconventional shape.

"When you have something this small, the atoms tend to aggregate and that can reduce the surface area," Xia says. "A key reason our technique works is the ability to keep the platinum arms fixed. They don't move around. This adds to their stability. We also make sure of the arrangement of atoms on each arm, so we increase the activity."

Xia and his collaborators are exploring the possibility of adding other noble metals such as gold to the bimetallic catalysts, making them trimetallic. Gold has been shown to oxidize carbon monoxide, making for even more robust catalysts that can resist the poisoning by carbon monoxide a reduction byproduct of some fuels.

"Gold should make the catalysts more stable, durable and robust, giving yet another level of control," Xia says.

####

For more information, please click here

Contacts:
Susan Killenberg McGinn
Exec. Dir. of Danforth Campus Communications

(314) 935-5254

Subject Matter Experts:
Younan Xia

Work: (314) 935-8328

Copyright © Washington University

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

Graphene and quantum dots put in motion a CMOS-integrated camera that can see the invisible May 29th, 2017

Ag/ZnO-Nanorods Schottky diodes based UV-PDs are fabricated and tested May 26th, 2017

New metamaterial-enhanced MRI technique tested on humans May 26th, 2017

Controlling 3-D behavior of biological cells using laser holographic techniques May 26th, 2017

Discoveries

Graphene and quantum dots put in motion a CMOS-integrated camera that can see the invisible May 29th, 2017

Ag/ZnO-Nanorods Schottky diodes based UV-PDs are fabricated and tested May 26th, 2017

New metamaterial-enhanced MRI technique tested on humans May 26th, 2017

Controlling 3-D behavior of biological cells using laser holographic techniques May 26th, 2017

Announcements

Graphene and quantum dots put in motion a CMOS-integrated camera that can see the invisible May 29th, 2017

Ag/ZnO-Nanorods Schottky diodes based UV-PDs are fabricated and tested May 26th, 2017

New metamaterial-enhanced MRI technique tested on humans May 26th, 2017

Controlling 3-D behavior of biological cells using laser holographic techniques May 26th, 2017

Energy

Three-dimensional graphene: Experiment at BESSY II shows that optical properties are tuneable May 24th, 2017

Stanford scientists use nanotechnology to boost the performance of key industrial catalyst May 18th, 2017

Fed grant backs nanofiber development: Rice University joins Department of Energy 'Next Generation Machines' initiative May 10th, 2017

Discovery of new transparent thin film material could improve electronics and solar cells: Conductivity is highest-ever for thin film oxide semiconductor material May 6th, 2017

Fuel Cells

Stanford scientists use nanotechnology to boost the performance of key industrial catalyst May 18th, 2017

MIT Energy Initiative awards 10 seed fund grants for early-stage energy research May 4th, 2017

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Scientists boost catalytic activity for key chemical reaction in fuel cells: New platinum-based catalysts with tensile surface strain could improve fuel cell efficiency December 19th, 2016

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