High selectivity of benzene electrochemical oxidation to p-benzoquinone on modified PbO2 electrode

- Uniform PbO2 surface layer with a pyramidal-angular structure.
- High oxygen evolution potential of the modified electrode.
- High selectivity of benzene electrochemical oxidation toward p-benzoquinone.

In this paper, a modified Ti/SnO2-Sb2O3/PbO2 electrode was successfully synthesized. The interlayer SnO2-Sb2O3 was obtained through thermal decomposition and the surface layer by electrochemical deposition. The structures and morphology of the layers were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical property was carried out by cyclic voltammogrametry (CV) and the products obtained from electrochemical oxidation of benzene were investigated by gas chromatography and mass spectrometry (GC-MS). The results showed that the surface of the prepared electrode was mainly composed of tetragonal-shaped β-PbO2 crystal with a pyramidal-angular structure. The oxidation potential of benzene was +1.8 V vs. Ag/AgCl. The electrochemical oxidation of benzene showed the high selectivity toward p-benzoquinone on the modified Ti/SnO2-Sb2O3/PbO2 electrode. And the optimal oxidation temperature for oxidation of benzene was 75 °C and the optimal temperature was 60 min.