Electrochemical degradation of p-substituted phenols of industrial interest on Pt electrodes. : Attempt of a structure–reactivity relationship assessment

The electrochemical oxidation of p-substituted phenols, with both electron donor (OH– and NH 2–) and electron withdrawing groups (NO 2–, COOH–, and halogens), on Pt anodes using sodium sulfate as support electrolyte has been studied. It was found that, except for p-halogen phenols, compounds with electron donor substituents are easier to remove and their initial rates of degradation are correlated to the octanol–water partitioning coefficient (log P oct) and the Hammett’s constant. Degradation of all of our starting compounds produced the same intermediates, therefore, a general pathway of reaction is proposed. Additionally, the influence of pH, temperature, electrolyte concentration and current density on the initial and total degradation of p-chlorophenol was also investigated.