A proton exchange membrane fuel cell (PEMFC) consists of a cathode, anode, and electrolyte membrane. Hydrogen is oxidized at the anode, producing protons that pass through the membrane to the cathode. Oxygen is reduced at the cathode, producing water and electricity. PEMFCs operate between 60-180 degrees C and use platinum catalysts. They are well suited for applications like fuel cell vehicles and small stationary power due to their moderate operating temperatures and manageable polymer materials.