A series of acetic acid-based ionic liquids (ILs) were synthesized and used for oxidative desulfurization as both catalyst and extractant. The practical and orthogonal experiments showed that [Otbim]+CH3COO- containing eight-carbon side chain has of best catalytic activity. 87.5% of thiophene in the model oil was removed under the optimal conditions of oxidation temperature at 70 degrees C, oxidation time of 180 min, simulated oil dosage of 10 ml, and ILs/H2O2 volume ratio of 1:1.1. Meanwhile, the ILs could be recycled 5 times without any apparent loss of the catalytic activity. (c) 2012 Elsevier B.V. All rights reserved.