Nanocomposite Fe203/SBA-15: An efficient and stable catalyst for the catalytic wet peroxidation of phenolic aqueous solutions

Abstract

In this work, the catalytic wet peroxide oxidation of phenolic aqueous solutions over a novel Fe2O3/SBA-15 nanocomposite material was deeply studied. The catalytic performance was monitored in terms of aromatics and total organic carbon (TOC) removals. In order to reduce the major operation cost, significant operating reactions parameters that affect remarkably the overall catalytic performance of these processes, such as temperature and hydrogen peroxide concentration, were studied by means of a design of experiments. High temperature is necessary to obtain a fast and complete degradation of aromatic compounds. At 100ºC, moderate catalyst loading and hydrogen peroxide concentration (0.6 g/L and 75 % of stoichiometric amount for phenol mineralization, respectively) were enough to achieve a total removal of aromatic compounds and remarkable TOC mineralization under non-controlled pH conditions. Resistance of iron species to be leached out into the aqueous solution has been also carefully examined with the purpose of elucidating the influence of different reaction parameters (temperature, oxidant concentration and pH). A schematic view of the heterogeneous catalytic peroxidation of phenol over this novel catalyst has been proposed. Finally, the stability of the catalyst has been established by recycling studies.