
16 Fuel Cells
made porous for easy transport of reactant gases toward electrolyte. This also
leads to higher contact area between the gas, electrode, and the electrolyte.
In a fuel cell, a direct hydrogen–oxygen combustion reaction is replaced by
two electrochemical half reactions at two electrode–electrolyte interfaces. The
hydrogen and oxygen reactants are spatially separated by the electrolyte.
The electrons released from breaking the hydrogen bond transfer through
an external circuit to recombine with oxygen and form water as the new
hydrogen–oxygen bond. The electrochemical reactions at the anode and
Water
Electricit
2
2
FIGURE 1.7 ...