Ketones from acid condensation using supported CeO2 catalysts: Effect of additives Original Research Article

Metal-doped, supported CeO2/Al2O3 catalysts are effective for the high temperature decarboxylative condensation of carboxylic acids to produce ketones. Representative catalysts were characterized based on H2 chemisorption, thermogravimetric reduction and coke analysis, and X-ray absorption spectroscopies at the Ce LIII-, K and Co K-, and Pd LIII-edges.Supported (on Al2O3) CeO2 (∼15–20 wt.%) catalysts selectively catalyze the condensation of isobutyric acid to diisopropyl ketone and that of acetic acid and decanoic acid to methylnonylketone. Catalysts are stable in long-term operation, with periodic regeneration. The optimal temperature range is 470–480 °C for the former reaction and 400–420 °C for the latter. For the former reaction, doping supported CeO2 catalysts with most transition metals, or with strongly basic or acidic additives, catalyzed a variety of side reactions, but the addition of small amounts of Co that dissolved in CeOx could increase the yield to desired ketone. For the latter reaction, certain group VIII metals added to CeO2 catalysts in higher concentrations proved beneficial, particularly Co or Pd.