The kinetics of oxidation of toluene by cerium(IV) in sulfuric media

The oxidation of toluene by Cerium(IV) has been followed spectrophotometric ally in the solution containing H2SO4, Na2SO4 and NaClO4. The effects of to luene, hydrogen ion and sulfate ion concentration as well as of the ionic s trength on the reaction rate have been studied. The main reaction product, identified by eas-chromatography, is benzyl alcohol, besides a small amount of benzaldehyde. The kinetic study revealed a two-stage process. fn the fi rst stage, an adduct between toluene and Ce(IV) is formed, undergoing elect ron transfer during the second stage. Both stages obey first-order kinetics relative to Ce(IV). A complex dependence of pseudo- first-order rare const ants on toluene, sulfate and hydrogen ions has been found. Activation param eters are calculated for adduct formation and oxidation process respectivel y, and a reaction mechanism has been suggested.