Metal-containing ZSM-5 (MZSM-5) molecular sieves were prepared and characterized by XRD, EDX, SEM and N-2-physisorption. The prepared MZSM-5 catalysts were found to be very effective for cyclohexane oxidation with tert-butyl-hydroperoxide in ionic liquid [emim]BF4 under mild conditions. Good yields and high selectivity of products were found in the ionic liquid compared within molecular solvent. The catalytic activity of FeZSM-5 was superior to that of other MZSM-5 and the as-received HZSM-5 in ionic liquid. For cyclohexane oxidation catalyzed by FeZSM-5, 20.9% conversion of cyclohexane and 98.2% selectivity of desired products were obtained in ionic liquid at the temperature of 90 degrees C. The catalyst/ionic liquid system could be successfully recycled by a simple decantation procedure without significant loss of activity. (c) 2007 Published by Elsevier B.V.