We studied the oxidation reaction of phenol in aqueous and acetonitrile media under mild conditions, employing Cu-modified MCM-41 mesoporous catalysts. The stability of the catalysts under reaction conditions was confirmed by XRD, UV-VIS and FTIR techniques. Results obtained indicate that the selective oxidation of phenol with H2O2 by a radical substitution mechanism produces three main reaction products: catechol, hydroqinone and benzoquinone.