Free Energy
www.businessinsider.com/r-ultra-strong-graphenes-weak-spot-could-be-key-to-fuel-cells-2014-11
LONDON (Reuters) -
In a discovery that experts say could revolutionize fuel cell
technology, scientists in Britain have found that graphene, the world's
thinnest, strongest and most impermeable material, can allow protons to
pass through it.
The researchers, led by the Nobel prize winner and discoverer of
graphene Andre Geim of Manchester University, said their finding also
raised the possibility that, in future, graphene membranes could be used
to "sieve" hydrogen gas from the atmosphere to then generate
electricity.
"We are very excited about this result because it opens a whole new
area of promising applications for graphene in clean energy harvesting
and hydrogen-based technologies," said Geim's co-researcher on the
study, Marcelo Lozada-Hidalgo.
Graphene, the thinnest material on earth at just one atom thick, and
200 times stronger than steel, was first isolated in 2004 by Geim and
fellow researchers, who were awarded a Nobel Prize in 2010 for their
work.
It is renowned for being impermeable to all gases and liquids, giving
it the potential for a range of uses such as corrosion-proof coatings,
impermeable packaging and even super-thin condoms.
Knowing that graphene is impermeable to even the smallest of atoms,
hydrogen, Geim's team decided to test whether protons, or hydrogen atoms
stripped of their electrons, were also repelled. Their work was
published in the journal Nature.
Against expectations, they found the protons could pass through the
ultra-strong material fairly easily, especially at raised temperatures
and if the graphene films were covered with nanoparticles such as
platinum, which acted as a catalyst.
Flickr/ UCL Mathematical and Physical Sciences
Geim and Lozada-Hidalgo, explaining their finding in a telephone
briefing for reporters, said this meant graphene could in future be used
in proton-conducting membranes, a crucial component of fuel cell
technology.
Fuel cells, used in some modern cars, use oxygen and hydrogen as fuel
and convert the input chemical energy into electricity. But a major
problem is that the fuels leak across the existing proton membranes,
"poisoning" the process and reducing the cells' efficiency -- something
Geim said could be overcome using graphene.
The team also found that graphene membranes could be used to extract
hydrogen from the atmosphere, suggesting the possibility of combining
them with fuel cells to make mobile electric generators powered just by
the tiny amounts of hydrogen in the air.
"Essentially, you pump your fuel from the atmosphere and get
electricity out of it," Geim said. "Our (study) provides proof that this
kind of device is possible."
