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