Optimizing calcination temperature of Fe/activated carbon catalysts for CWPO

Abstract

The influence of the calcination temperature (within the temperature range 150–300 °C) on the chemical nature of the surface as well as on the activity of an own-made Fe/AC catalyst for catalytic wet peroxide oxidation (CWPO) has been studied. The catalyst surface was characterized by means of TG, TPD and N 2 adsorption/desorption analysis. The presence of iron promotes the oxidation of the activated carbon surface, increasing the amount of oxygen surface groups, mainly carboxylic acid, anhydride and lactone groups. On the other hand, the calcination step modifies the distribution of these groups, increasing the amount of lactone groups and reducing the pH slurry. Within the temperature range studied, the calcination temperature does not affect to the porous structure. The changes observed in the catalyst surface led to an increase of the catalytic activity as a consequence of a higher H 2O 2 decomposition into OH radicals, probably due to a better dispersion of the active phase. Neither oxygen surface groups by themselves nor pH slurry seemed to have influence on the catalytic activity.