Catalytic transfer hydrogenation of 2-butanone over oxide catalysts

Catalytic transfer hydrogenation of 2-butanone with 2-propanol was studied in gas phase over a series of oxides of different acid-base properties. Although the basic oxides (MgO, La₂O₃) gave high initial conversions, these oxides underwent deactivation during the reaction. This deactivation could be partially prevented by a previous treatment with chloroform of the oxide. The amphoteric oxides (TiO₂, ZrO₂, Al₂O₃) were also active in this reaction. Increasing the acidic character of the catalyst (Nb₂O₅, WO₃) led to a pronounced dehydration of 2-propanol. The results obtained over a series of rare earth oxides (La₂O₃, Sm₂O₃, Gd₂O₃, Dy₂O₃, Er₂O₃) revealed that beside the role of basic and acid sites a correlation seems to exist between the number of unpaired electrons of the metal ion and the catalytic activity, indicating the role of one electron donor sites.