Novel metal modified diatomite, zeolite and carbon xerogel catalysts for mild conditions wet air oxidation of phenol: Characterization, efficiency and reaction pathway

Metal (Co, Ce, Ni, Fe, Zn, Mn and Cu) containing Diatomite (D), Zeolite (Z) and Carbon Xerogel (CX) catalysts were prepared, characterized (SEM-EDX, TEM, FTIR and XRD) and tested as new catalysts in Catalytic Wet Air Oxidation (CWAO) of phenol in aqueous solution. Maximum values of Chemical Oxygen Demand (COD) or Total Organic Carbon (TOC) efficiencies were obtained in the case of Fe-D, Cu-Z, and Co-CX catalysts. Reaction pathway and kinetics for CWAO of phenol revealed a pseudo first-order catalytic process and a k(cat) between 0.0473 x 10(-3) and 1.4183 x 10(-3) L/min g. (Di)carboxylic acids, acetic and oxalic were identified as oxidation organic products.