Catalysts made of carbon nanotubes dipped in a polymer solution equal the energy output and otherwise outperform platinum catalysts in fuel cells, a team of Case Western Reserve University engineers has found.
The researchers are certain that they'll be able to boost the power output and maintain the other advantages by matching the best nanotube layout and type of polymer.
But already they've proved the simple technique can knock down one of the major roadblocks to fuel cell use: cost.
Platinum, which represents at least a quarter of the cost of fuel cells, currently sells for about $65,000 per kilogram. These researchers say their activated carbon nanotubes cost about $100 per kilogram.
Their work is published in the online edition of Journal of the American Chemical Society at http://pubs.acs.org/doi/full/10.1021/ja1112904.
"This is a breakthrough," said Liming Dai, a professor of chemical engineering and the research team leader.
Dai and research associates Shuangyin Wang and Dingshan Yu found that by simply soaking carbon nanotubes in a water solution of the polymer polydiallyldimethylammoniumn chloride for a couple of hours, the polymer coats the nanotube surface and pulls an electron partially from the carbon, creating a net positive charge.
They placed the nanotubes on the cathode of an alkaline fuel cell. There, the charged material acts as a catalyst for the oxygen-reduction reaction that produces electricity while electrochemically combining hydrogen and oxygen.
In testing, the fuel cell produced as much power as an identical cell using a platinum catalyst.
But the activated nanotubes last longer and are more stable, the researchers said. Unlike platinum, the carbon-based catalyst: doesn't lose catalytic activity and, therefore, efficiency, over time; isn't fouled by carbon monooxide poising; and is fre
|Contact: Kevin Mayhood|
Case Western Reserve University