The water
vapours produced during the reaction
were condensed and added to the
drinking water supply for the astronauts 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