The prospect of running small devices on
electricity generated from a simple fuel cell running on
atmospheric hydrogen and oxygen has been raised by research at the
University of Oxford.
Professor Fraser Armstrong used an enzyme
rather than an expensive platinum catalyst to promote the oxidation
of hydrogen, and his ‘biofuel’ cell generated electricity with no
membrane – conventionally used to separate the reactants in the
cell. It also worked in the presence of carbon monoxide, which
poisons most catalysts.
“For small applications, maybe even
nano[scale], our fuel cell will produce electricity from just
traces of hydrogen in air,” said Armstrong. “That’s really novel
because you can’t do that with any conventional fuel cell, you need
a membrane.”
Because the enzyme used by Armstrong is
completely unaffected by carbon monoxide, it could be used to build
fuel cells that function in polluted environments. However, work
needs to be done on understanding how the enzyme works, probably
improving it, and on developing applications for potential small
cells.
“The direction in the future would have to
be to make more robust enzymes, ones that can survive for months,
if not years,” said Armstrong. “The electrode materials should be
developed to accommodate enzymes in a permanent and robust manner.
The enzymes themselves can be genetically modified - you can
manipulate micro organisms to produce catalysts for novel energy
technologies. It’s a way off yet, but this is a proof of
concept.”
One obvious job will be to come up with
applications for the cell. Armstrong said they would inevitably be
small scale, but not much has been developed beyond that. “We’re
looking for applications,” he said. “If we can find that there is a
future of some sort for this type of technology, we would be very
interested to move to that level.”
www.chem.ox.ac.uk/researchguide/faarmstrong.html