Decomposition of 2-propanol over vanadium pentoxide and modified vanadium pentoxide catalysts

Abstract

The catalytic decomposition of 2-propanol has been investigated in a flow system from 200-300°C on vanadium pentoxide and modified vanadium pentoxide catalysts. Dehydration, dehydrogenation and propane formation were observed over the temperature range studied. The propane reaction was predominant at higher temperatures. Kinetic experiments showed the dehydration and dehydrogenation reactions to be zero order with respect to all components while the propane- forming reaction was found to have a rate order of 0.3 with respect to 2-propanol. The kinetics for the reactions were interpreted in terms of the Langmuir-Hinshelwood model and elimination type mechanisms have been proposed to account for the 2-propanol decomposition. Trends in activity and activation energies for the dehydration reaction have been correlated with the mobility of surface oxygen previously reported in the literature. Some correlations were obtained with activation energies for dehydration reactions in similar systems. The reduction of the catalysts used, as indicated by changes in surface area and X-ray powder diffraction patterns, has been related to oxygen mobility and to the surface 'Tammann* temperature of the additive.