Sandwich structure enables cheaper, more efficient hydrogen fuel cells
By Darren Quick
March 19, 2012
For the predicted hydrogen economy to become a reality, fuel cells must become more efficient and cost effective. Researchers from the University of Central Florida (UCF) claim to have addressed both these problems by creating a sandwich-like structure that allows more abundant materials to be used as catalysts in hydrogen fuel cells.
Current hydrogen fuel cells generally rely on catalysts made of platinum, which is rare and expensive. Unfortunately there aren’t many alternatives because most elements can’t resist the corrosive process that converts hydrogen’s chemical energy into electrical power. Platinum and iridium are up to the task, but both are also rare and expensive, while gold and palladium – although less expensive – don’t stand up very well to the highly acidic solvents present in the chemical reaction within fuel cells.
In an effort to make gold and palladium better suited for the chemical reaction, UCF Professor Sergey Stolbov and postdoctoral research associate Marisol Alcántara Ortigoza layered cheaper and more abundant elements with gold and palladium in a sandwich-like structure.
Below a top (outer monoatomic) layer of either gold or palladium they positioned a layer that enhances the energy conversion rate of the fuel cell while also protecting the catalyst from the acidic environment. These two top layers sit upon a bottom layer made of an inexpensive tungsten substrate that also acts to stabilize the catalyst. The researchers say this structure allows more energy to be converted, while also reducing the cost as rarer and more expensive metals aren’t needed.
“We are very encouraged by our first attempts that suggest that we can create two cost-effective and highly active palladium- and gold-based catalysts –for hydrogen fuel cells, a clean and renewable energy source,” Stolbov said.
Stolbov says the team’s approach is quite reliable but that experiments need to be conducted to test their predictions and determine whether it has the potential for large-scale application. They are working with a group within the U.S. Department of Energy to try and duplicate the results.
Stolbov’s team’s research appears in The Journal of Physical Chemistry Letters.
Source: University of Central Florida