Unraveling the surface reactions during liquid-phase oxidation of benzyl alcohol on Pd/A1(sub 2)O(sub 3): An in Situ ATR-IR study

The palladium-catalyzed liquid-phase reaction of benzyl alcohol to benzaldehyde was investigated in the presence and absence of oxygen by attenuated total reflection infrared (ATR-IR) spectroscopy. The occurrence of the hydrogenolysis of the C-O bond of benzyl alcohol and formation of toluene indicates that Pd was present in a reduced state Pd(super 0) even in the presence of oxygen, in agreement with the dehydrogenation mechanism of alcohol oxidation.