Inorganic and Applied Chemistry

Download free books at BookBooN.com

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