Graphical Abstract: The intact activated carbon CAN-8, obtained from nutshells by activation with water vapours, in the presence of oxygen and at relatively low temperatures, possesses catalytic activity, caused by the presence of alkaline functional groups on its surface, as well as by the formation, in these experimental conditions, of the OH radical, which has a high oxidation potential. After 25 cycles of the process of methylene blue oxidation, the data of chromatographic analyses indicate the presence of three organic components in the solution.