Catalytic wet air oxidation of p-coumaric acid on CeO2, platinum and gold supported on CeO2 catalysts

p-Coumaric acid is representative of the polyphenolic fraction typically found in olive milling waste waters (OMWW). The catalytic wet air oxidation of p-coumaric acid has been investigated at 353 K at P = 2 MPa, using CeO2, Pt and Au supported on CeO2 catalysts. The influence of the metal and of the preparation method of the catalysts on the catalytic activity has been investigated. Upon addition of Pt to CeO2, the rate of oxidation of p-coumaric acid increases whereas addition of gold do not lead to a significant difference of the activity of CeO2. On all the catalysts investigated, the abatement of total organic carbon (TOC) was >= 80% after 300 min of reaction. Catalysts containing metallic platinum are the most effective towards the mineralization of the organic carbon to CO2 and the degree of mineralization (DM%) was higher than 50%. On CeO2 and Au-CeO2 catalysts a great contribute to the abatement of TOC is given from a significant adsorption of the organic substrates on the solid. (c) 2006 Elsevier B.V. All rights reserved.