Fuel Cell Operation
Briefly, the chemistry involves the combination of hydrogen and oxygen into water.
2 Hydrogen molecules (H2), each comprised of 2 hydrogen atoms, enter through the hydrogen inlet port on the left. As they contact the left electrode, which contains platinum as a catalyst, the 4 Electrons (e-) of these 2 molecules are stripped away and exit through the electrical circuit.
The 4 Hydrogen Ions (H+), which are Protons, pass through the electrolyte membrane, thus the term "Proton Exchange Membrane."
At the right electrode the 4 Hydrogen Ions combine with the 4 Electrons returning from the outside circuit and one Oxygen (O2) molecule entering through the right air inlet port. The 2 Water Molecules (H2O) produced then exit through the right air outlet port.
During the process 4 Nitrogen Molecules (N2) also pass through with the Oxygen Molecule, but donít participate in the reaction. The Nitrogen Molecules are displayed to show the fact that in most applications atmospheric air is used instead of pure oxygen.