Activated carbons prepared from walnut shells and coals have been used as supports for silver. The effects of precursor type, heating mode and activation temperature on the surface properties of the supports have been tested. Low-temperature nitrogen sorption, X-ray diffraction, scanning and transmission electron microscopy have been used to characterize a series of silver-modified samples. The results show that silver nanoparticles strongly determine textural properties as well as the amount and type of surface oxygen groups generated on the surface of the activated carbons. The impregnation of these activated carbons with silver species leads to the formation of attractive catalysts for the oxidation of cyclohexene with hydrogen peroxide. (c) 2012 Elsevier B.V. All rights reserved.