Novel nanowires to make fuel cells more durable and efficient

April 1st, 2011 - 5:37 pm ICT by ANI  

Washington, April 01(ANI): Engineers at the Yale School of Engineering and Applied Science have created a new fuel cell catalyst system using nanowires made of a novel material that boosts long-term performance by 2.4 times compared to today’s technology.

Jan Schroers and Andre Taylor have developed miniscule nanowires made of an innovative metal alloy known as a bulk metallic glass (BMG) that have high surface areas, thereby exposing more of the catalyst.

They also maintain their activity longer than traditional fuel cell catalyst systems.

Current fuel cell technology uses carbon black, an inexpensive and electrically conductive carbon material, as a support for platinum particles.

The carbon transports electricity, while the platinum is the catalyst that drives the production of electricity.

The more platinum particles the fuel is exposed to, the more electricity is produced.

Yet carbon black is porous, so the platinum inside the inner pores may not be exposed. Carbon black also tends to corrode over time.

“In order to produce more efficient fuel cells, you want to increase the active surface area of the catalyst, and you want your catalyst to last,” said Taylor.

At 13 nanometers in scale (about 1/10,000 the width of a human hair), the BMG nanowires are about three times smaller than carbon black particles.

The nanowires’ long, thin shape gives them much more active surface area per mass compared to carbon black. In addition, rather than sticking platinum particles onto a support material, the Yale team incorporated the platinum into the nanowire alloy itself, ensuring that it continues to react with the fuel over time.

It’s the nanowires’ unique chemical composition that makes it possible to shape them into such small rods using a hot-press method, said Schroers.

The BMG nanowires also conduct electricity better than carbon black and carbon nanotubes, and are less expensive to process.

So far Taylor has tested their catalyst system for alcohol-based fuel cells (including those that use ethanol and methanol as fuel sources), but they say the system could be used in other types of fuel cells and could one day be used in portable electronic devices such as laptop computers and cell phones as well as in remote sensors.

“This is the introduction of a new class of materials that can be used as electrocatalysts. It’s a real step toward making fuel cells commercially viable and, ultimately, supplementing or replacing batteries in electronic device,” he added.

The findings appear on the cover of the April issue of ACS Nano. (ANI)

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