Dioxomolybdenum(vi) complex immobilized on ascorbic acid coated TiO2 nanoparticles catalyzed heterogeneous oxidation of olefins and sulfides

Abstract

Addition of MoO₂ (acac)₂ to TiO₂ coated with ascorbic acid (AA) under ultrasonic agitation resulted in a nanohybrid (TiO₂/AA/MoO₂) with size ranging between 20–25 nm. The structural and morphological characterization of the as-prepared nanohybrid was carried out by different techniques such as XRD, FT-IR, TGA and transmission electron microscopy (TEM). The catalytic performance of the TiO₂/AA/MoO₂ nanocomplex in the heterogeneous oxidation of olefins and sulfides using H₂O₂ in ethanol as a safe solvent was exploited. Our results clearly demonstrated the efficiency, selectivity and oxidative stability of the heterogeneous nanocatalyst providing its effective reusability and removing by-products. The catalytic activity of the TiO₂/AA/MoO₂ nanocomplex was strikingly different from other nanometer sized metal oxides such as m-ZrO₂, MoO₃, Fe₃O₄ and TiO₂, as well as their nanocomposites such as TiO₂/AA, ZrO₂/AA/MoO₂, MoO₃/AA/MoO₂ and Fe₃O₄/AA/MoO₂.