In the cell, hydrogen and oxygen are
bubbled through porous carbon
electrodes into concentrated aqueous
sodium hydroxide solution 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