A boost for fuel cells
Researchers at the University of Houston (UH) have developed a new platinum-based catalyst for fuel cells that is at least four times more efficient and cheaper than existing catalysts. This discovery in fuel cell research may ease reliance on gasoline. According to the researchers, the active phase of the catalyst consists of nanoparticles with a platinum-rich shell and a core made of an alloy of copper, cobalt, and platinum. But it's not enough for this new catalyst to be more efficient and cheaper than a pure platinum one. It also needs to work for a long time -- say, the life of a car. So far, the preliminary results look promising, but longer-term testing is needed before this kind of fuel cells can be used to power your car.
This research project has been led by Peter Strasser, assistant professor of chemical and biomolecular engineering at the UH Cullen College of Engineering. His research team included Ratndeep Srivastava, a graduate student, Prasanna Mani, a postdoctoral researcher, and Nathan Hahn, a 2007 UH graduate. You can see on the left a photo of Strasser examining a catalyst material being tested for use in polymer electrolyte membrane fuel cells. (Credit: UH)
The UH news release is quite informative, defining what is a fuel cell in exactly two lines. "A fuel cell converts chemically stored energy directly into electricity and is already two to three times more efficient in converting fuel to power than the internal combustion engine usually found in automobiles."
It also explains the costs associated with a fuel cell. "The key to making a fuel cell work is a catalyst, which facilitates the reaction of hydrogen and oxygen. The most common, but expensive, catalyst is platinum. Currently, the amount of platinum catalyst required per kilowatt to power a fuel cell engine is about 0.5 to 0.8 grams, or .018 to .028 ounces. At a cost of about $1,500 per ounce, the platinum catalyst alone would cost between $2,300 to $3,700 to operate a small, 100-kilowatt two- or four-door vehicle -- a significant cost given that an entire 100-kilowatt gasoline combustion engine costs about $3,000. To make the transition to fuel cell-powered vehicles possible, the automobile industry wants something better and cheaper."
In fact, the car companies want to use a platinum-based catalyst that is four times more efficient or four times cheaper than current catalysts. And this is what the UH researchers are delivering. "'We have found a low platinum alloy that we pre-treat in a special way to make it very active for the reaction of oxygen to water on the surface of our catalyst,' Strasser said. 'A more active catalyst means that we get more electricity, or energy, for the amount of platinum used and the time it’s used for. With a material four to six times more efficient, the cost of the catalyst has reached an important target set by industrial fuel cell developers and the U.S. Department of Energy.'"
If you want to learn more about this discovery, the research work has been published online on September 24, 2007 by the Angewandte Chemie International Edition journal under the name "Electrocatalysis on Voltammetrically De-alloyed Pt-Cu-Co Nanoparticles." Here is a link to the paper, which has no abstract, but can be purchased for $25.
And for even more information, you can read two other UH Cullen College of Engineering documents, "Going Green" (from which the picture of Strasser has been extracted) and "Engineering Researchers Make Fuel Cell Breakthrough" (September 21, 2007.
Sources: University of Houston news release, October 29, 2007; and various websites
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