Electrochemical Oxidation of Phenol

The electrochemical oxidation of phenol was studied using a packed bed reactor of pellets with recirculating anolyte in order to follow phenol loss and benzoquinone, maleic acid, and carbon dioxide formation. A carbon mass balance revealed a significant fraction of additional by‐products for initial phenol concentrations of ⩾ 0.014M. Benzoquinone and carbon dioxide formation were measured as a function of applied current, initial phenol concentration, electrolyte acid concentration, temperature, and dissolved oxygen. Benzoquinone formation was favored by high current and acid concentration and by low phenol concentration, temperature, and dissolved oxygen at relatively short electrolysis times. Carbon dioxide formation depended on the degree of the oxidation and was favored by high current, acid concentration, temperature, dissolved oxygen, and by low phenol concentration.