New 'Biofuel Cell' Produces Electricity from Hydrogen in Plain Air

[jpak]

http://www.azom.com/details.asp?newsID=8100

A pioneering 'biofuel cell' that produces electricity from ordinary air spiked with small amounts of hydrogen offers significant potential as an inexpensive and renewable alternative to the costly platinum-based fuel cells that have dominated discussion about the 'hydrogen economy' of the future, British scientists reported here today.

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Fraser Armstrong, Ph.D., described how his research group at Oxford University built the biofuel cell with hydrogenases - enzymes from naturally occurring bacteria that use or oxidize hydrogen in their metabolism. The cell consists of two electrodes coated with the enzymes placed inside a container of ordinary air with 3 percent added hydrogen.

That is just below the 4 percent danger level at which hydrogen becomes an explosion hazard. The research established for the first time that it is possible to generate electricity from such low levels of hydrogen in air, Armstrong said.

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"The technology is immensely developable," Armstrong said. "We are at the tip of a large iceberg, with important consequences for the future, but there is still much to do before this generation of enzyme-based fuel cells becomes commercially viable. The idea of electricity from hydrogen in air, using an oxygen-tolerant hydrogenase is new, although other scientists have been investigating enzymes as electrocatalysts for years. Most hydrogenases have fragile active sites that are destroyed by even traces of oxygen, but oxygen tolerant hydrogenases have evolved to resist attack."

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