Catalytic wet air oxidation of acetic acid over different ruthenium catalysts

Ruthenium catalysts were prepared by impregnation of different supports: ZrO(2), CeO(2), TiO(2), ZrO(2)-CeO(2) and TiO(2)-CeO(2). Their activities for acetic acid oxidation in aqueous solution were investigated in a stirred reactor at a reaction temperature of 200 degrees C and total pressure of 4 MPa. The order of the catalyst activity obtained was RuO(2)/ZrO(2)-CeO(2) > RuO(2)/CeO(2) > RuO(2)/TiO(2)-CeO(2) > RuO(2)/ZrO(2) > RuO(2)/TiO(2), which corresponds to surface concentration of non-lattice oxygen (defect-oxide or hydroxyl-like group) of these catalysts. The non-lattice oxygen on the catalyst surface plays an important role in the catalytic activity. (C) 2008 Elsevier B.V. All rights reserved.