Catalytic wet peroxide oxidation of phenol over mixed [Al-Cu]-pillared clays

Various processes can be used for the treatment of wastewater, but the one we feel to be important and more promising is the wet peroxide oxidation (WPO), in the presence of a solid catalyst, at atmospheric pressure and at room temperature. Different types of materials can be used as catalysts for such reactions, but as shown in previous studies dealing with phenol oxidation clays-based catalysts seem to be attractive. It is well known that natural clays are inactive in the phenol oxidation, but the intercalation of polymeric species changes their properties. When the clay is pillared with pure aluminum oxyhydroxides species, the d(001) spacing and the surface area increase, but the activity is very low. When the clay is pillared with mixed [Al-Cu] there is a strong increase of the phenol conversion. Nevertheless W (Wyoming) based solids are more active than H (Haidoudi) or L (Laponite) based catalysts. The stability, the activity and the percentage of copper depend on the preparation method.