Question

Calculate the maximum cell potential for the H₂ and O₂ fuel cell.

Please include calculations.

Answer 1

The ideal standard potential of an H2/O2 fuel cell (E0) is 1.229 V. This can be evaluated as follows :

H2 + ½ O2 ==> H2O

standard free energy change of the fuel cell reaction is given by the following equation

∆G = –nFE

Where ∆G is the free energy change, n is the number of moles of electrons involved, E is the reversible potential, and F is Faraday’s constant. If the reactants and the products are in their standard states, the equation can be represented as ∆G0 = –nFE0

The value of ∆G is −229 kJ/mol,

n = 2, F = 96500C/g.mole electron,

and hence the calculated value of E is 1.229 V.