Pulling electricity out of air may be a feasible option
in the future according to researchers at Oxford University. Fraser Armstrong,
Ph.D. and his research team have managed to develop
a revolutionary bio fuel cell which promises clean and renewable energy.
The bio fuel cell contains two electrodes that are covered
with oxygen-sensitive FeFe hydrogenase enzymes. The enzymes are attached to the
electrodes using strong covalent and non-covalent linkages to allow for fast
electron transfers. The electrodes and enzymes are then placed within a container
of air which has a 3% mixture of hydrogen.
Current testing shows that the prototype fuel cell is
capable of powering small electronic devices such as a wristwatch.
"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," said
Armstrong. "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."
Armstrong notes that typical hydrogen fuel cells require
expensive metals like platinum ($1,000 USD per ounce) to serve as a catalyst
for electricity production. Hydrogenases also have roughly the same
productivity rate as platinum-based catalysts and do not require complex
fuel-separation membranes to operate.