Tuesday, April 07, 2009

Yet another fuel cell advance

Huh. A few (dozen) more of these, and I might have to rethink my pessimism on fuel cells in general.
A new synthetic route yields inexpensive iron-based catalysts for fuel cells that are nearly as active catalytically as the expensive platinum catalysts normally used in those electrochemical devices, scientists in Canada report in Science (2009, 324, 71). The study advances efforts to come up with low-cost substitutes for precious-metal catalysts and may help lower the high price of fuel cells for automotive applications.

A key obstacle to widely commercializing hydrogen-fueled electric automobiles is the cost of the fuel cells that convert hydrogen into electric power. Polymer-electrolyte-membrane (PEM) fuel cells, the type widely studied for powering cars, generally include carbon-supported platinum (Pt/C) catalysts to mediate reactions at the electrodes. For years, researchers have worked on lowering overall costs by replacing platinum with less expensive substitutes such as iron, which is generally considered a leading candidate. But until now, iron-based catalysts have remained too sluggish, especially for driving the oxygen-reduction reaction, which converts oxygen to water at the cathode.
The main drawback so far is that while the performance is initially almost as powerful as more expensive platinum-based FCs, they degrade rather quickly. However, the researchers believe that a stable iron-based catalyst should be possible, given that similar arrangements are found in nature.

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