Catalytic wet-air oxidation of p-cresol was carried out on Ag/Al2O3-ZrO2 catalysts at 1, 5, 10, and 20 wt % of ZrO2 in a reactor-type batch and 160 degrees C and 15 bar of oxygen. Al2O3-ZrO2 supports were prepared by the simultaneous hydrolysis of the boehmite and zirconium alkoxide. Ag/Al2O3-ZrO2 catalysts prepared by deposition precipitation showed higher surface area (202-216 m(2)/g) and lower Lewis acids sites than the Ag/Al2O3 (161 m(2)/g) and Ag/ZrO2 (25 m(2)/g) reference catalysts. FTIR-CO adsorption showed a shift to lower frequencies on Ag/Al2O3-ZrO2 catalyst indicating electron-rich metallic particles. The p-cresol conversion, TOC. abatement, and CO2 selectivity were improved when Ag was supported on Al2O3-ZrO2 mixed oxides. A modification of the surface properties of Ag on the Ag/Al2O3-ZrO2 catalysts due to a metal support interaction leading to a faster oxidation of the adsorbed reactant species is proposed.