Catalysts like
finely divided platinum or palladium
metal are incorporated into the electrodes
for increasing the rate of electrode
reactions The electrode reactions are
given below:
Cathode:
O2(g) + 2H2O(l) + 4e–¾® 4OH–(aq)
Anode:
2H2 (g) + 4OH–(aq)  ¾® 4H2O(l) + 4e–
Overall reaction being:
2H2(g) + O2(g) ¾® 2H2O(l )
The cell runs continuously as long as the reactants are supplied Fuel cells produce electricity with an efficiency of about 70 % compared
Fig 2