Polymer could cut fuel cell costs.

A conducting polymer grown on the same material used to make waterproof raincoats could provide a cheap and plentiful alternative to platinum in fuel cells.

Most hydrogen fuel cells currently rely on platinum to catalyse the splitting of hydrogen into protons and electrons at one electrode, and to reduce oxygen so the hydrogen protons and electrons can combine to form water at the other electrode.

The researchers from Monash University in Australia created a polymer-based electrode that can reduce oxygen as effectively as platinum. The group coated a porous Goretex membrane with an ultra-thin, 40nm, layer of gold to improve the electrode's conductivity. They then 'grew' layers of poly(3,4-ethylenedioxythiophene) (PEDOT) on the Goretex using vapour phase polymerisation. The electrode operated for 1500 hours without any deterioration in the material (Science 2008, 321, 671).

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Using a layer of gold to improve the electrode's conductivity is, author Douglas MacFarlane admits, swapping one expensive metal for another. But he adds that the amount of gold used is miniscule and they are already working to replace it with other, more common metals. And the monomer of PEDOT is readily available and could be much cheaper if it were rolled-out in large scale applications.

Chris Rhodes, an independent energy consultant, says it is a 'nice piece of work'. However, he adds, 'This is not a solution but one of so many technological "solutions" that cannot be implemented fast enough to replace or cheapen the cost of oil-based transport.'

MacFarlane also concedes that they have only solved half the problem. A hydrogen electrode that does not rely on platinum is still needed, which he describes as 'a big challenge'.