Hydrogen Fuel Cell

Hydrogen at the anode and Oxygen at the cathode combine to form water. The reduction of Hydrogen at the anode causes the lost electrons to form a current on their way to reducing oxygen at the cathode.

2 H2 -> 4 H+ + 4 e-

O2 + 4 e-  -> 2 O2-

2 O2- + 4 H+  -> 2 H2O