Fuel Oxidations by Oxygen Layers

In order to see the true inhibition in the potential region where the current decreases with potential, a correction has to be made for the gradient of the concentration of H2 in the diffusion layer. The partial 

The quantity I14 bPHjPn is plotted in Fig. 35 as a function of U. At the same time the oxygen coverage expressed by Qo/2s6h is shown. The results in Fig. 35 demonstrate that the inhibition is large at small oxygen 

The inhibition of the oxidation of organic fuels by the oxygen layer is similar to that of the H2 oxidation on platinum. The methanol oxidation wave obtained [117] during the anodic sweep with 30 mV/sec on smooth platinum in 1M HCIO4 +1M CH3OH at 30 C is shown as an example in Fig. 36 a. The current rises with potential between 0.7 V and 0.9 V. 

Subsequently it decreases with U between 0.9 V and 1.1 V. The coverage QoJsQox with adsorbed carbonaceous species (see section 4 of chapter DC) and the oxygen coverage were also determined [60] under the same voltammetric conditions. Both coverages are plotted as a function of potential in Fig. 36 b. The coverage with carbonaceous species decreases 

Fleischmann, M., J. R. Mansfield, and Lord Wynne-Jones J. Electroanalyt. 

---