Synthesis of nano Ag catalyst embedded vanadium phosphorus oxide for oxidation of styrene to benzaldehyde by hydrogen peroxide

Abstract

In this work, silver nanocatalyst loaded on vanadium phosphorus oxide (Ag/VPO) for oxidation of styrene to benzaldehyde was synthesized by method including impregnating of VPO substrate with colloid solution of Ag nanoparticles (NPs). VPO substrate was prepared by microwave-assisted reaction of vanadium and phosphorus precursors. Meanwhile, Ag/PVP NPs with the size of 7.5 nm and spherical shape, determined by transmission electron microscopy (TEM), were prepared in solution using NaBH4 as reducing agent and polyvinylpyrrolidone (PVP) as protecting agent. The Ag/VPO catalyst with Ag loading of 10.5 % providing by atomic emission spectroscopy (AES) was gained. The immobile of Ag on VPO was evidenced by XRD, UV-VIS spectroscopy, scanning electron microscopy (SEM), and TEM imaging. SEM and TEM showed that the morphology of Ag-VPO is insignificantly different from the pristine VPO. The Ag/VPO catalyst was characterized in oxidation reaction of styrene to benzaldehyde in which the products were determined by gas chromatography (GC) coupled with flame ionization detector (FID). The results showed that the conversion of styrene reaching high value of > 97.5 % after reaction time of one hour.