Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Nanowires May Lead To Better Fuel Cells

'Electron microscope view of platinum nanowires with beads.'

Credit - University of Rochester
'Electron microscope view of platinum nanowires with beads.'

Credit - University of Rochester

Abstract:
The creation of long platinum nanowires at the University of Rochester could soon lead to the development of commercially viable fuel cells.

Described in a paper published today in the journal Nano Letters, the new wires should provide significant increases in both the longevity and efficiency of fuel cells, which have until now been used largely for such exotic purposes as powering spacecraft. Nanowire enhanced fuel cells could power many types of vehicles, helping reduce the use of petroleum fuels for transportation, according to lead author James C. M. Li, professor of mechanical engineering at the University of Rochester.

Nanowires May Lead To Better Fuel Cells

Rochester, NY | Posted on March 11th, 2009

"People have been working on developing fuel cells for decades. But the technology is still not being commercialized," says Li. "Platinum is expensive, and the standard approach for using it in fuel cells is far from ideal. These nanowires are a key step toward better solutions."

The platinum nanowires produced by Li and his graduate student Jianglan Shui are roughly ten nanometers in diameter and also centimeters in length—long enough to create the first self-supporting "web" of pure platinum that can serve as an electrode in a fuel cell.

Much shorter nanowires have already been used in a variety of technologies, such as nanocomputers and nanoscale sensors. By a process known as electrospinning—a technique used to produce long, ultra-thin solid fibers—Li and Shui were able to create platinum nanowires that are thousands of times longer than any previous such wires.

"Our ultimate purpose is to make free-standing fuel cell catalysts from these nanowires," says Li.

Within a fuel cell the catalyst facilitates the reaction of hydrogen and oxygen, splitting compressed hydrogen fuel into electrons and acidic hydrogen ions. Electrons are then routed through an external circuit to supply power, while the hydrogen ions combine with electrons and oxygen to form the "waste" product, typically liquid or vaporous water.

Platinum has been the primary material used in making fuel cell catalysts because of its ability to withstand the harsh acidic environment inside the fuel cell. Its energy efficiency is also substantially greater than that of cheaper metals like nickel.

Prior efforts in making catalysts have relied heavily on platinum nanoparticles in order to maximize the exposed surface area of platinum. The basic idea is simple: The greater the surface area, the greater the efficiency. Li cites two main problems with the nanoparticle approach, both linked to the high cost of platinum.

First, individual particles, despite being solid, can touch one another and merge through the process of surface diffusion, combining to reduce their total surface area and energy. As surface area decreases, so too does the rate of catalysis inside the fuel cell.

Second, nanoparticles require a carbon support structure to hold them in place. Unfortunately, platinum particles do not attach particularly well to these structures, and carbon is subject to oxidization, and thus degradation. As the carbon oxidizes over time, more and more particles become dislodged and are permanently lost.

Li's nanowires avoid these problems completely.

With platinum arranged into a series of centimeter long, flexible, and uniformly thin wires, the particles comprising them are fixed in place and need no additional support. Platinum will no longer be lost during normal fuel cell operation.

"The reason people have not come to nanowires before is that it's very hard to make them," says Li. "The parameters affecting the morphology of the wires are complex. And when they are not sufficiently long, they behave the same as nanoparticles."

One of the key challenges Li and Shui managed to overcome was reducing the formation of platinum beads along the nanowires. Without optimal conditions, instead of a relatively smooth wire, you end up with what looks more like a series of interspersed beads on a necklace. Such bunching together of platinum particles is another case of unutilized surface area.

"With platinum being so costly, it's quite important that none of it goes to waste when making a fuel cell," says Li. "We studied five variables that affect bead formation and we finally got it—nanowires that are almost bead free."

His current objective is to further optimize laboratory conditions to obtain fewer beads and even longer, more uniformly thin nanowires. "After that, we're going to make a fuel cell and demonstrate this technology," says Li.

####

About University of Rochester
The University of Rochester (www.rochester.edu) is one of the nation's leading private universities. Located in Rochester, N.Y., the University gives students exceptional opportunities for interdisciplinary study and close collaboration with faculty through its unique cluster-based curriculum. Its College of Arts, Sciences, and Engineering is complemented by the Eastman School of Music, Simon School of Business, Warner School of Education, Laboratory for Laser Energetics, Schools of Medicine and Nursing, and the Memorial Art Gallery.

For more information, please click here

Contacts:
Evan Wendel

585.275.2671

Copyright © University of Rochester

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

Continuous roll-process technology for transferring and packaging flexible LSI August 29th, 2016

Meteorite impact on a nano scale August 29th, 2016

Designing ultrasound tools with Lego-like proteins August 29th, 2016

A nanoscale wireless communication system via plasmonic antennas: Greater control affords 'in-plane' transmission of waves at or near visible light August 27th, 2016

Discoveries

Continuous roll-process technology for transferring and packaging flexible LSI August 29th, 2016

Meteorite impact on a nano scale August 29th, 2016

Designing ultrasound tools with Lego-like proteins August 29th, 2016

A promising route to the scalable production of highly crystalline graphene films August 26th, 2016

Announcements

Continuous roll-process technology for transferring and packaging flexible LSI August 29th, 2016

Meteorite impact on a nano scale August 29th, 2016

Designing ultrasound tools with Lego-like proteins August 29th, 2016

A nanoscale wireless communication system via plasmonic antennas: Greater control affords 'in-plane' transmission of waves at or near visible light August 27th, 2016

Energy

New electrical energy storage material shows its power: Nanomaterial combines attributes of both batteries and supercapacitors August 25th, 2016

Lehigh engineer discovers a high-speed nano-avalanche: New findings published in the Journal of Electrochemical Society about the process involving transformations in glass that occur under intense electrical and thermal conditions could lead the way to more energy-efficient glas August 24th, 2016

New flexible material can make any window 'smart' August 23rd, 2016

Researchers reduce expensive noble metals for fuel cell reactions August 22nd, 2016

Fuel Cells

Researchers reduce expensive noble metals for fuel cell reactions August 22nd, 2016

W.M. Keck Foundation awards Cal State LA a $375,000 research and education grant August 4th, 2016

Proton pinball on the catalyst: Moisture helps catalyst in fuel cells August 3rd, 2016

New nontoxic process promises larger ultrathin sheets of 2-D nanomaterials July 27th, 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







Car Brands
Buy website traffic