Various Fenton-like catalysts prepared by choline chloride (ChCl) and metal salts (FeCI3, ZnCl2, SnCl2) were characterized by FT-IR, UV-vis, Raman, ESI-MS and elemental analysis. High desulfurization efficiency of dibenzothiophene (DBT) could be obtained not only in hydrophilic ionic liquid (IL) [Bmim]BF4 (94.9%) but also in hydrophobic IL [Omim]BF4 (97.2%) by using ChFeCl(4) as a catalyst under mild conditions. ESR measurements could give the evidence that the active oxygen species generated by ChFeCl(4) and H2O2 in IL were involved in the catalytic oxidation of DBT. The influential factors, including reaction time, temperature, catalyst dosage, and O/S (H2O2/DBT) molar ratio, were investigated in detail to estimate the optimal conditions for the desulfurization system in [Omim]BF4. The aromatic sulfur compounds, DBT, benzothiophene (BT), and 4,6-dimethyldibenzothiophene (4,6-DMDBT), could be oxidized to the corresponding sulfones, which were detected by GC-MS. Moreover, the catalytic system containing IL and catalyst could be easily separated from oil and could be recycled at least five times without a significant decrease on removal of DBT. (C) 2013 Elsevier B.V. All rights reserved.