Electrocatalytic activity and simultaneous determination of catechol and hydroquinone at mesoporous platinum electrode

The electrochemical oxidation of catechol and hydroquinone was investigated using cyclic and differential pulse voltammetries at nanostructured mesoporous platinum film electrochemically deposited from the hexagonal liquid crystalline template of C₁₆EO₈ surfactant. The mesoporous platinum electrode has shown an excellent electrocatalytic activity and reversibility towards the oxidation of catechol and hydroquinone redox isomers in 1.0 M HClO₄. The oxidation and reduction peak separation (ΔE) has been decreased from 485 to 55 mV for hydroquinone and from 430 to 75 mV vs. SCE for catechol at polished polycrystalline and mesoporous platinum electrodes, respectively. The differential pulse voltammograms in a mixture solution of catechol and hydroquinone have shown that the oxidation peaks became well resolved and are separated by about 100 mV, although the bare electrode gave a single broad oxidation peak. Moreover, the oxidation current of hydroquinone and catechol has been enhanced by a factor of two and four times, respectively, at mesoporous platinum electrode. Using differential pulse voltammetry, a highly selective and simultaneous determination of hydroquinone and catechol has been explored at mesoporous platinum electrode.