At the anode the hydrogen molecules give up electrons and form hydrogen ions, a process that is made possible by the platinum catalyst.

The electrons travel to the cathode through an external circuit, producing electrical work as they go through the light bulb.

The hydrogen ions flow through the proton exchange membrane to the cathode, where they combine with oxygen molecules to form water.

In this way, hydrogen fuel's natural tendency to oxidize and form water produces electricity and useful work.

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

The chemical reaction: