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Inorganic and Applied Chemistry
Example 6- J:
Fuel cells
A fuel cell is in principle a galvanic cell where the reactants are added continuously to the system. In order
to illustrate the principle in a fuel cell reaction we will look at the exothermal reaction between methane
and oxygen which is a redox reaction:
CH 4 (g) + 2 O 2 (g) CO 2 (g) + 2 H 2 O(g) + energy
The energy that is developed by the process is normally used to heat up houses or to run engines. In a fuel
cell the energy may be extracted as electrical energy directly as the transferred electrons may be extracted
directly. Similarly, the simple reaction hydrogen and oxygen:
H 2 (g) + O 2 (g) 2 H 2 O(l)
may be used to extract current through a fuel cell set-up as sketched in the figure below:
Figure 6- 9: Fuel cell
Sketch of the principle set-up in a fuel cell.
Electrochemistry