Catalytic wet air oxidation of phenol over metal catalyst (Ru,Pt) supported on TiO2–CeO2 oxides

•Ru and Pt supported on sol–gel-derived TiO2–xwt% CeO2.•High oxygen storage capacities of the materials are detrimental to catalytic performances.•The presence of Lewis acid sites promotes the phenol total oxidation. The catalytic performances of Ru and Pt supported on TiO2–xwt% CeO2 were studied in catalytic wet air oxidation (CWAO) of phenol at 160°C and 20bar of pure oxygen pressure. Contrary to expectations, improved oxygen storage capacities of the materials prove to be detrimental to catalytic performances since they favor the formation of polymers in solution and the accumulation of adsorbed species. On the opposite, the presence of Lewis acid sites promotes the phenol total oxidation. They would favor the activation of the hydroxyl function, thus promoting the ortho-oxidation of phenol and finally the formation of CO2. On the other hand, platinum appears to be more efficient than ruthenium for CWAO of phenol.