Highly active phosphotungstic acid immobilized on amino functionalized MCM-41 for the oxidesulfurization of dibenzothiophene

Phosphotungstic acid H3PW12O40 (HPW) was successfully immobilized on the surface of MCM-41 functionalized with amino groups. The obtained catalysts were characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectra, thermo-gravimetric analysis, and inductively coupled plasma atomic emission spectroscopy. The results indicated that the surface area of MCM-41 support decreased after it was functionalized with amino groups, whereas the HPW active species retained its Keggin structure. HPW–NH2–MCM-41 exhibited excellent catalytic performance for oxidesulfurization (ODS) of dibenzothiophene (DBT). Under optimal conditions, the conversion of DBT reached up to 100%. The catalyst could be recycled five times without significant loss of catalytic activity. The excellent recyclability was attributed to the strong interaction between the amino groups and the HPW species. •HPW-NH2-MCM-41 catalyst retained mesoporous structure of MCM-41.•Using HPW-NH2-MCM-41 as catalyst, the conversion of DBT was almost 100%.•No significant activity reduction was observed after five recycles of the catalyst.