Degradation of naphthalene by liquid-phase oxidation over ordered mesoporous V-m-TiO2 catalysts

The vanadium species doped mesoporous anatase TiO2 samples were successfully synthesized via a facile one-pot EISA method. The physical chemical properties were characterized by XRD, N2 sorption, UV–Vis, Py-IR, SEM, TEM and XPS techniques, and the catalytic performance were also investigated in the oxidation of naphthalene with hydrogen peroxide. The vanadium species with 4+ or 3+ valence can be homogeneously tetrahedrally incorporated into the mesoporous framework of anatase TiO2, and it would increase the Bronsted acidity resulting in the promotion of catalytic performance. Naphthalene conversion of 26.1% can be obtained over 10 V-m-TiO2 sample in the absence of ascorbic acid. The catalytic performance was much higher than other samples with the same loading of vanadium species prepared by impregnation or coprecipitation even though they were in the presence of ascorbic acid as reductant. Although the intrinsic reusability for 10 V-m-TiO2 sample was poor, the catalytic performance was promoted and the catalytic reusability can be kept well by introduction of ascorbic acid into the oxidation system even after repeated reaction for five times.