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

Sirrus's Issued Patent Portfolio Continues To Accelerate July 18th, 2018

FEFU scientists reported on toxicity of carbon and silicon nanotubes and carbon nanofibers: Nanoparticles with a wide range of applying, including medicine, damage cells of microalgae Heterosigma akashivo badly. July 18th, 2018

In borophene, boundaries are no barrier: Rice U., Northwestern researchers make and test atom-thick boron's unique domains July 17th, 2018

Tuning into quantum: Scientists unlock signal frequency control of precision atom qubits July 16th, 2018

Discoveries

FEFU scientists reported on toxicity of carbon and silicon nanotubes and carbon nanofibers: Nanoparticles with a wide range of applying, including medicine, damage cells of microalgae Heterosigma akashivo badly. July 18th, 2018

In borophene, boundaries are no barrier: Rice U., Northwestern researchers make and test atom-thick boron's unique domains July 17th, 2018

Tuning into quantum: Scientists unlock signal frequency control of precision atom qubits July 16th, 2018

UMBC researchers develop nanoparticles to reduce internal bleeding caused by blast trauma July 13th, 2018

Announcements

Sirrus's Issued Patent Portfolio Continues To Accelerate July 18th, 2018

FEFU scientists reported on toxicity of carbon and silicon nanotubes and carbon nanofibers: Nanoparticles with a wide range of applying, including medicine, damage cells of microalgae Heterosigma akashivo badly. July 18th, 2018

In borophene, boundaries are no barrier: Rice U., Northwestern researchers make and test atom-thick boron's unique domains July 17th, 2018

Tuning into quantum: Scientists unlock signal frequency control of precision atom qubits July 16th, 2018

Energy

NIST Researchers Simulate Simple Logic for Nanofluidic Computing June 30th, 2018

Northwestern researchers achieve unprecedented control of polymer grids: Materials could find applications in water purification, solar energy storage, body armor June 22nd, 2018

Physicists devise method to reveal how light affects materials: The new method adds to the understanding of the fundamental laws governing the interaction of electrons and light June 15th, 2018

Tripling the Energy Storage of Lithium-Ion Batteries: Scientists have synthesized a new cathode material from iron fluoride that surpasses the capacity limits of traditional lithium-ion batteries June 14th, 2018

Fuel Cells

Harvesting clean hydrogen fuel through artificial photosynthesis May 3rd, 2018

A new way to find better battery materials: Design principles could point to better electrolytes for next-generation lithium batteries March 29th, 2018

Rice sleuths find metal in 'metal-free' catalysts: Study of graphene catalysts finds trace of manganese, suggests better ultrathin fuel-cell components February 26th, 2018

Study boosts hope for cheaper fuel cells: Rice University researchers show how to optimize nanomaterials for fuel-cell cathodes January 6th, 2018

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



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project