FUEL CELLS

How the PEM Fuel Cell Works
A PEM (Proton Exchange Membrane, also called Polymer Electrolyte Membrane) fuel cell uses a simple chemical reaction to combine hydrogen and oxygen into water, producing electric current in the process. For those interested in the chemistry, it works something like electrolysis in reverse:

1. At the anode, hydrogen molecules give up electrons, forming hydrogen ions. This process is made possible by the platinum catalyst.

2. The proton exchange membrane allows protons to flow through, but not electrons. As a result, the hydrogen ions flow directly through the proton exchange membrane to the cathode, while the electrons flow through an external circuit.

3. As they travel to the cathode through the external circuit, the electrons produce electrical current. This current can perform useful work by powering any electrical device (such as an electric motor or a light bulb).

4. At the cathode, the electrons and hydrogen ions combine with oxygen to form water.

5. In a fuel cell, hydrogen's natural tendency to oxidize and form water produces electricity and useful work.

6. No pollution is produced and the only byproducts are water and heat.

Anode:	2H2	--->	4H+ + 4e-
Cathode:	4e- + 4H+ + O2	--->	2H2O
Overall:	2H2+ O2	--->	2H2O

 

Visit the links above to learn more about fuel cells

SERC's Stack-in-a-Box®, a portable fuel cell power supply system. photo by Kellie Jo Brown