Proton-coupled electron transfer from an interfacial phenol monolayer

Martin Sjödin*, Johan Hjelm, A. William Rutherford, Robert Forster

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

A tert-butyl protected phenol is covalently link to a mixed self-assembled monolayer on a gold or platinum electrode. The phenol reduction potential shows the expected pH-dependence of a one-electron, one-proton couple with a decrease in formal reduction potential of 59 ± 5 mV per pH. A titration of the phenol is observed with a pKa of 13.2 and the reduction potential for the phenolate is 0.11 V. NHE. The kinetic behavior of the proton-coupled oxidation deviates substantially from the commonly used models for a step-wise reaction that assume the proton transfer reactions are in equilibrium throughout the reaction. A novel model for step-wise proton-coupled reactions is presented that fully accounts for the pH dependent kinetics and allows the formal rate constants and the transfer coefficients to be determined.

Original languageEnglish
Article number113856
JournalJournal of Electroanalytical Chemistry
Volume859
Number of pages8
ISSN1572-6657
DOIs
Publication statusPublished - 2020

Keywords

  • Kinetic models
  • pH dependence
  • Phenol-terminated alkane-thiol monolayer
  • Proton-coupled electron transfer

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