Abstract

The oxidation of Br− and I− on Pt electrodes in HClO4 was found to be selectively inhibited by phenol. The rate of oxygen evolution is essentially unaltered under the same experimental conditions. The species causing inhibition is not phenol but a radical (most likely O·) formed from it in an anodic charge transfer adsorption process. The initial potential for inhibition was related to the concentration of phenol in solution and to the pH. The adsorption of the radical is controlled by the combined effects of charge transfer and competition with adsorbed water molecules. Very good agreement with the theory of electrosorption of organic species based on a competition-with-water model is obtained. The number of water molecules replaced by each phenol radical is five, indicating that the radical is adsorbed through the oxygen atom, with the aromatic ring at an angle to the surface. Very high fractional surface coverages were found (values of 1-σ being in the range 10−2–10−4) in the potential region where inhibition takes place.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.