Electrochemical Oxidation Decomposition of Benzene by Intermediates
N. V. Chaenko1, G. V. Kornienko2, N. G. Maksimov3, V. L. Kornienko4
1 Institute of Chemistry and Chemical Technology
2 Institute of Chemistry and Chemical Technology
3 Institute of Chemistry and Chemical Technology
4 Institute of Chemistry and Chemical Technology, kvl@icct.ru
Abstract
Indirect electrochemical oxidation of benzene by intermediates has been studied. The intermediates were generated in situ from О2, Н2О, and Н2О2 with the use of anodes from platinum, lead dioxide, and ruthenium-titanium oxide anode in water solutions with various рН. Schemes with in situ generated Н2O2 from О2 and with Н2O2 adding to electrolyte have been implemented. It was found that hydroxylation of benzene to produce phenol with a gas diffusion cathode from commercial-grade carbon that generates Н2О2 from О2 in situ is ineffective because of the cathode passivation. On Н2О2 addition into the electrolyte, oxidation of benzene occurred with mineralization to yield СО2 and Н2O; the oxidation state could amount from 94.8 % (Pb/PbO2, рН 2) to 63.5 % (Pt-anode, рН 2.8, СFe2+ = 7.1 ⋅ 10-6 mg/L). Efficiency of oxidation drops owing to the formation difficult-to-oxidize carboxylated complexes of iron.
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