Kinetics of the reaction of cyclohexene with the surface of a manganese dioxide

The reaction of cyclohexene with the surface oxygens of MnO₂ produces benzene and water. The kinetics of this irreversible chemisorption has been studied in a flow system. The influence of cyclohexene pressure on the rate of benzene formation, suggests that the surface reaction is rate determining. The number of reactive oxygens has been shown to be increasing with the temperature, reaching a value close to half of the total surface oxygen. The temperature dependency of the number of reactive oxygens, follows the same pattern as the initial rate of reduction (8 kcal/mole). The rate-determining step could thus be the availability of the sites, as was already assumed by Taylor and Thon for the kinetics of chemisorption.