Question

Explain the working principle of Phosphoric Acid Fuel Cell (PAFC).

Answer 1

Phosphoric acid fuel cells (PAFC) operate at temperatures around 150 to 200 C (about 300 to 400 degrees F).

As the name suggests, PAFCs use phosphoric acid as the electrolyte. Positively charged hydrogen ions migrate through the electrolyte from the anode to the cathode.
Electrons generated at the anode travel through an external circuit, providing electric power along the way, and return to the cathode.
There the electrons, hydrogen ions and oxygen form water, which is expelled from the cell. A platinum catalyst at the electrodes speeds the reactions.

The formation of carbon monoxide (CO) around electrodes can "poison" a fuel cell.