Ultra-deep oxidative desulfurization of real fuels by sandwich-type polyoxometalate immobilized on copper ferrite nanoparticles, Fe6W18O70 ⊂ CuFe2O4, as an efficient heterogeneous nanocatalyst

Abstract

In order to obtain the clean gasoline, we report on the synthesis and characterization of a new heterogeneous nanocatalyst comprised of the sandwich-type polyoxotungstate [(FeW9O34)2Fe4(H2O)2]−10 (Fe6W18O70) clusters and copper ferrite (CuFe2O4) nanoparticles. The materials were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV–vis), and scanning electron microscopy (SEM). The Fe6W18O70⊂CuFe2O4 nanocatalyst catalyzed the oxidative desulfurization (ODS) reactions of hazardous sulfur-containing compounds by H2O2-CH3COOH as oxidant. The nanocatalyst exhibited an exceptionally high catalytic performance in the ultra-deep ODS of simulated fuels and real gasoline. The experimental results revealed that the oxidation reaction efficiencies were up to 95% at the temperature of 35 °C and the contact time of 1 h. Particularly, the removal (%) of thiophene (C4H4S), benzothiophene (C8H6S), and dibenzothiophene (C12H8S) from simulated fuels over Fe6W18O70⊂CuFe2O4 nanocatalyst could reach 98%, 99%, and 99%, respectively. Moreover, the heterogeneous nanocatalyst could be easily recovered and reused multiple times by filtration with no obvious loss of activity. The present study will lead to the widespread catalytic application of Fe6W18O70⊂CuFe2O4 material in the efficient and feasible ODS of petroleum fractions.