A fuel cell is an electrochemical device that
combines hydrogen fuel and oxygen from the air
to produce electricity, heat and water. Fuel
cells operate without combustion, so they are
virtually pollution free. Since the fuel is
converted directly to electricity, a fuel cell
can operate at much higher efficiencies than
internal combustion engines, extracting more
electricity from the same amount of fuel. The
fuel cell itself has no moving parts - making it
a quiet and reliable source of power.
The video above
shows how a fuel cell produces electricity. The
fuel cell is composed of an anode (a negative
electrode that repels electrons), an electrolyte
in the center, and a cathode (a positive
electrode that attracts electrons).
As hydrogen flows
into the fuel cell anode, a platinum catalyst on
the anode helps to separate the gas into protons
(hydrogen ions) and electrons. The electrolyte
in the center allows only the protons to pass
through the electrolyte to the cathode side of
the fuel cell. The electrons cannot pass through
this electrolyte and flow through an external
circuit in the form of electric current. This
current can power an electric load, such as the
light bulb shown in the video.
As oxygen flows
into the fuel cell cathode, another platinum
catalyst helps the oxygen, protons, and
electrons combine to produce pure water and
cells can be then combined into a fuel cell
"stack." The number of fuel cells in the stack
determines the total voltage, and the surface
area of each cell determines the total current.
Multiplying the voltage by the current yields
the total electrical power generated.