Correlation between structural evolution and oxidative desulfurization activity for magnetically-recoverable γ-Fe2O3@SiO2 core-shell–Supported WOx nanostructure

Abstract

In this work, the effect of calcination temperature on the preparation of WOx catalysts supported on γ-Fe2O3@SiO2 core-shell nanostructure is reported. Powder XRD and Raman results evidenced that during calcination between 400 and 600°C, the SiO2 shell hinders the phase transition of the formed γ-Fe2O3 to α-Fe2O3, thus maintaining the superparamagnetic characteristics of the core. According to TEM images, a sintering process of SiO2 shell occurs at high temperature, leading to the reduction of the surface area. Because the enhanced dispersion of dioxo (O=)2WO2 species, the γ-Fe2O3@SiO2 catalyst calcined at 500 °C presented impressive performance in the catalytic oxidation of dibenzothiophene.

Keywords

• Tungsten oxide
• Core-shell
• Magnetic catalysts
• Oxidative desulfurization