The Catalytic Dehydrogenation of Butanols over the Silica-Copper ( II ) and -Zinc ( II ) Prepared by the Homogeneous Method

Abstract

The catalytic dehydrogenation of butanols over the silica-copper(II) and -zinc(II), which were prepared by the precipitation method from homogeneous solution at pH 8, was compared with those of the catalysts prepared by usual coprecipitation method. Dehydrogenation took place selectively over the catalysts prepared by both methods. The catalytic dehydrogenation activities on the homogeneous catalysts were much higher than those on the coprecipitated catalysts, and the order of activity was Cu(II)>Zn(II), and 1-butanol>2-methyl-l-propanol>2-butanol.
Kinetic studies using a flow reactor indicated that the dehydrogenation was of first-order irreversible reaction. From the Arrhenius plots the activation energies for the dehydrogenation of 1-butanol, 2-methyl-1-propanol and 2-butanol over the homogeneous silica-copper(II)were found to be 12.1, 16.0 and 41.2 kcal/mol·g, respectively.