1. In H2 – O2 fuel cell, hydrogen and oxygen are bubbled through porous carbon electrodes into concentrated aqueous NaOH solution, which acts as the electrolyte. The electrode reactions are,
Anode : 2H2(g) + 4 OH-(aq) → 4 H2O(l) + 4\(\bar e\)
Cathode : O2(g) + 2 H2O(l) + 4\(\bar e\) → 4 OH-(aq)
Overall reaction : 2H2(g) + O2(g) → 2 H2O(l)
2. The advantages of fuel cells over other cells
- They are pollution free.
- More efficient than conventional methods.
- Runs continuously as long as the reactants are supplied.
- Electrodes are not affected.