SURFACE-CHEMISTRY OF BENZOYL COMPOUNDS ON OXIDES, AN FT-IR STUDY

Adsorption and surface reactions on various oxides have been monitored by IR spectroscopy, with benzaidehyde, benzoic acid, methylphenylketone. and 2-phenyl-2-propanol. The oxides were chosen to represent typical adsorption properties (SiO2 γ-Al2O3, and α-Mn3O4). Surface reactions were observed at various temperatures, starting from room temperature. The results concern three points: (i) identification of adsorbed species, arising on different oxides under increasing temperatures; (ii) the possible sequence of reaction steps in the insertion (oxidation) or removal (reduction) of oxygen, into or from the molecules studied; and (iii) the conclusion that a Cannizzaro reaction is not likely so that the insertion (and removal) is most probably by the Mars and van Krevelen mechanism. © 1993 Academic Press, Inc.