Catalytic wet air oxidation of butyric acid and maleic acid solutions over noble metal catalysts prepared on TiO2

The catalytic wet air oxidation (CWAO) of butyric and maleic acids was carried out in a batch reactor operated at 333 K and at atmospheric pressure. Noble metals (platinum, palladium and ruthenium) supported on TiO2 were used as catalysts as well as commercial Pt/Al2O3, Maleic and butyric acids could be oxidized only into intermediates on the commercial Pt/Al2O3 catalysts with a conversion of 11% and 7.9%, respectively. Total oxidation to CO2 ranged from 0.0% to 0.35% for butyric acid (BA) and from 0.4% to 1.7% for maleic acid (MA). Intermediate products were oxalic and formic acids. In BA oxidation, acetic acid was also detected. (C) 2008 Elsevier B.V. All rights reserved.