Design

How a proton exchange membrane fuel cell (PEMFC) works.

In a PEM-Fuel Cell, the electrolyte is a thin polymer membrane that is permeable for protons, but not electrons. The electrodes are generally made of carbon. Hydrogen flows into the fuel-cell on the anode side, where it is split into hydrogen ions (protons) and electrons. The hydrogen ions begin to flow through the electrolyte to the cathode, while the electrodes circulate externally, creating an electric current. Oxygen is then fed into the process on the cathode side as ambient air. This oxygen combines with the electrons and the hydrogen ions to create water.

The chemical reaction at the electrodes can be described as follows:

Anode: 2H2 4H+ + 4e-

Cathode: O2 + 4H+ + 4e- 2H2O

Entire reaction: 2H2 + O2 2H2O + electricity + heat

The fuel cell does not produce any toxins. Only water vapour is emitted.

For a detailed explanation of the process, click here...