Magnetically Recoverable Heterogeneous Catalyst: Tungstate Intercalated Mg–Al-Layered Double Hydroxides-Encapsulated Fe3O4 Nanoparticles for Highly Efficient Selective Oxidation of Sulfides with H2O2

Abstract

High catalytic activity of tungstate intercalated in hydrotalcite-encapsulated magnetic Fe3O4 nanoparticles have been prepared. High resolution transmission electron microscopy characterization demonstrated the formation of Fe3O4 nanoparticles within LDH matrix with a mean diameter of 1–3 nm. The catalyst of WO4 2−/LDH@Fe3O4 exhibited excellent catalytic activity for the oxidation of various sulfides. The magnetic properties of the WO4 2−/LDH@Fe3O4 provided a convenient route for separation of the catalyst from the reaction mixture by application of an external permanent magnet. The spent catalyst could be recycled without appreciable loss of catalytic activity. .