BACKGROUND: Activated carbons (AC) can be used as catalyst in advanced oxidation processes due to the potential activity for hydrogen peroxide decomposition to hydroxyl radicals. Chemical surface groups and textural properties can play a crucial role in its catalytic behaviour. The pH of the reaction medium can also affect the adsorption properties of AC and the chemistry of hydrogen peroxide in catalytic oxidation processes. The AC/H2O2 systems have been successfully used for the degradation of some organic pollutants in wastewaters over recent years. RESULTS: The influence of different modified-activated carbon cloth (ACC) samples has been studied. Commercial ACC samples were treated under neutral (H2O), acid (H3PO4), basic (NaOH) and oxidizing (H2O2) solutions. Modified-ACC samples were assessed in the adsorption (in absence of H2O2) and chemical advanced oxidation (in presence of H2O2) of phenol at different pH values. ACC samples hydrothermally treated showed the best adsorption properties. ACC samples treated with NaOH solutions evidenced the best catalytic performance for phenol oxidation under acidic conditions. CONCLUSIONS: The functionalization of ACC samples with basic surface groups yielded the best catalytic performance with total phenol removal and efficient use of the hydrogen peroxide at acidic conditions. (C) 2014 Society of Chemical Industry