Slides in this set
· What is a fuel cell?
· A electrochemical device that uses a
chemical reaction between hydrogen
and oxygen (or another oxidising
agent) to produce electricity and water.
· Who invented them?
· Fuel cells were invented by Sir William
Grove in 1842.
· At first fuel cells weren't efficient
· Modern fuel cells
· Modern fuel cells are based on
hydrogen or `hydrogen rich' reactants
such as methanol.
· Modern fuel cells were used in the
space shuttle launch.…read more
A SIMPLE FUEL CELL CONSISTS OF TWO ELECTRODES; AN ANODE
AND A CATHODE SEPARATED BY AN ELECTROLYTE .
· What happens at the Anode?
· Hydrogen will react with a catalyst to create one
proton (H+ Ion) and one electron (e- ). The proton
will then pass through the electrolyte while the
electron travels around the circuit therefore
creating a current.
· What happens at the Cathode?
· Oxygen will react with the proton (H+ Ion) and
the electron (e- ) to form water and a useful
amount of thermal energy.
(This cell will generate about 1.23v ,as shown in the
previous slide, which is enough to power one light
MAKING A FUEL CELL
Questions for the following
Pb Pb2+ + 2e-
PbO2 + 4H+ +2e- Pb2+ + 2H2O
What is the overall ionic equation?
Pb + PbO2 + 4H+ 2Pb2+ + 2H2O
What is formed at each electrode
give the equations
Hydrogen is formed at the cathode
and oxygen is formed at the anode.
2H+ + 2e H2
4OH 2H2O + O2 + 4e…read more
E CELL = E POSITIVE TERMINAL E NEGATIVE
2H2O + 2e- H2 + 2OH- E = -0.83V (negative
½O2 + H2O + 2e- 2OH- E = +0.40 (positive
E cell= +0.40 - -0.83 = 1.23V
Using the top right-bottom left rule you can
deduce the Cell reaction
Therefore, combining the two equations we get:
- - - -
· H + 2OH + ½O + H O + 2e 2OH + 2H O + 2e
2 2 2 2
· H + ½O H O
2 2 2
The flow of electrons from hydrogen to oxygen
creates a voltage.…read more
DIFFERENT TYPES OF FUEL CELLS
Fuel cells require a
fuel source such as
Natural gas create
Pollutants such as
advantage of these
is that they're
easier to store and
can be generated
from Biomass so
this overcomes the
problem of using
up all the finite