Role of the Activated Carbon Surface on Catalytic Wet Peroxide Oxidation

Three activated carbons with fairly different characteristics have been checked in catalytic wet peroxide oxidation (CWPO) using phenol as a model compound for the purpose of learning the role of these materials which can be used as supports for the preparation of Fe or other metallic catalysts. A complex contribution of mixed effects is involved making difficult to predict the behavior of a given activated carbon. The surface of these materials promotes the undesirable decomposition of H 2 O 2 to unreactive O 2 instead of • OH radicals in an extent depending on the nature and accessibility of the oxygen groups. A frankly basic surface including groups such as pyrone with an egg-shell type distribution on the carbon particle seems to be beneficial for a more effective decomposition of H 2 O 2 leading to a higher oxidation activity. The presence of iron in the activated carbon ashes is also an important factor which may hide in part other effects derived from the structure and surface composition of the carbon. However, that factor cannot explain by itself the differences found in the behavior of the activated carbons since two of them with a similar Fe content showed markedly different activities in CWPO of phenol.