Thermodynamics of the Oxygen Electrode

The overall four-electron reductions of O2 in acid and alkaline aqueous solutions are, respectively, 

This value is based on that in footnote b, but is open to question (see text). 

Standard Electrode Potentials of Selected Oxygen Reactions 

Hoare in his review of thermodynamic data for O2 lists a value of ( nhe)iii = 0.064 V at 25°C, calculated from thermodynamic data for the 

The stability of the peroxide is principally the result of the need for multielectron transfers with unstable intermediates requiring large increments in free energy and the difficulty of breaking the 0-0 bond. The latter results in the reduction reaction V being extremely slow. 

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