Kinetics and mechanism of oxidation of sugar and sugar alcohols by vanadium pentoxide

Abstract

The kinetics of oxidation of sugars and sugar alcohols by vanadium pentoxide (V2O5) in acidic medium have been investigated spectrophotometrically under pseudo-first order conditions and over a wide range of experimental conditions. Each reaction was first order with respect to the substrate and oxidant.The kinetic data for the oxidation by V2O5 solution showed that increase in temperature and sugar concentration increased the rate of the reactions. It was also observed that with increase in pH and KNO3 concentration, the reaction rate decreased with increase in V2O5 concentration with the exception of fructose which showed significant increase in reaction rates. The mechanism of these reactions involved the formation of a 1:1 intermediate complex. The order of reactivities of the sugars was Maltose > Fructose > Sucrose > Glucose > Sorbitol >Mannitol