H6GeMo10V2O40?16H2O nanoparticles prepared by hydrothermal method: a new and reusable heteropoly acid catalyst for highly efficient acetylation of alcohols and phenols under solvent-free conditions

摘要

A new Keggin-type heteropoly acid, namely decamolybdodivanadogermanic acid (H6GeMo10V2O40?16H2O), with nanosized particles (5-8 nm), has been synthesized by a hydrothermal method and characterized by elemental analysis, thermogravimetric analysis (TGA), powder X-ray diffractometry (XRD), Fourier-transform infrared spectroscopy (FTIR), UV-Visible spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and potentiometric titration. H6GeMo10V2O40?16H2O revealed high catalytic activity for acetylation of various alcohols and phenols with acetic anhydride at room temperature (298 ± 2 K) and under solvent-free conditions. The catalyst can be easily recovered and used repeatedly for five cycles with a slight loss of activity. The catalytic activity of H6GeMo10V2O40?16H2O was higher than that of other Keggin-type heteropoly acids, such as H3PW12O40, H3PMo12O40 and H4SiW12O40.