WET OXIDATION OF WASTE-WATER CONTAINING HYDROCARBONS BY NOVEL SUPPORTED PD CATALYSTS

Pd catalysts supported on TiO2, ZrO2, ZSM-5, MCM-41 and activated carb on were used in catalytic wet oxidation of hydrocarbons such as phenol , m-cresol and m-xylene. It was found that the Pd/TiO2 catalyst was hi ghly effective in the wet oxidation of hydrocarbon. The activities of catalysts with various hydrocarbon species, catalyst support, oxidatio n state of catalyst performed in a 3-phase slurry reactor show that re action on Pd surface is more favorable than that in aqueous phase and that the active site is oxidized Pd in catalytic wet air oxidation of hydrocarbons. Based on the experimental results, a plausible reaction mechanism of wet oxidation of hydrocarbons catalyzed over Pd/TiO2 cata lyst was proposed. This catalyst is superior to other oxide catalysts because it suppressed the formation of hardly-degradable organic inter mediates and polymer.