Carbon-Supported Platinum Catalysts: Influence of Activation Treatment of a Synthetic Carbon Support and of Metal Deposition in the Selective Liquid Phase Oxidation of Alcohols

Oxidations of alcohols into carbonyl functionalities are key reactions in the synthesis of fine chemicals. The need to substitute stoichiometric oxidations (using mineral oxidants) with "green" oxidations using benign oxidizing agents like molecular oxygen or hydrogen peroxide has been often emphasized. Supported noble metal catalysts, e.g. Pd/C or Pt/C are known to catalyse the oxidation of alcohols in the presence of molecular oxygen. It was previously reported that benzyl alcohol (Bzol) can be very selectively oxidized to benzaldehyde (Bzal) in dioxane, whereas the use of a 50/50 mixture of dioxane and alkaline aqueous solution yielded benzoic acid (Bzoic) by further oxidation of Bzal. In this work, we examined the effect of the activation treatment of the synthetic carbon and of the method of deposition of the metal on the characteristics of the supported metallic catalyst and its activity in this reaction. The highest dispersion and best catalytic performances were obtained by impregnation with hexachloroplatinic acid of a CO2 activated carbon.