Environmental Engineering Reference
In-Depth Information
particles from one electrode
to the other. Electrolytes can
be solids, liquids, or pastes. All
fuel cells also have a special
material called a
catalyst
. The
catalyst acts to speed up the
chemical reactions in the fuel
cell. Some fuel cells use metals
such as platinum, nickel, or iron
as electrodes or in the catalyst.
u
Outer Space
Water
NASA has long used liquid
hydrogen to fuel space rockets.
Now NASA also uses fuel cells
within the space shuttle cabin
to provide electrical power
to the shuttle's instruments.
The water that is created in
the fuel cell is then used as
drinking water by the crew.
Creating a
Chemical Reaction
In a hydrogen fuel cell,
hydrogen and oxygen are
needed for the reactions that
will create the l ow of electrons
that is electricity. This is how
it works. Hydrogen gas from a
tank is run through a tube or
pipe into the fuel cell at one
of two electrodes. A chemical
reaction causes the hydrogen
atoms to lose electrons. These
hydrogen atoms are now called
ions
. They are atoms that carry
a positive charge. The loose
electrons that left the original
hydrogen atoms l ow along a wire out of the fuel cell as part
of an electrical circuit. They produce the electricity.
Workers take apart a fuel cell that has been
removed from the space shuttle.
