Magdolna R. Mihályi

Catalytic Activity of Boron-Beta Zeolite Modified with Indium in the Epoxidation of Cinnamyl Alcohol

Liquid-phase epoxidation of cinnamyl alcohol was carried out with hydrogen peroxide as oxidizing agent using indium-containing boron- and aluminium-beta zeolites. It was proved that InO+ ions, created by oxidation of univalent indium cations incorporated into beta zeolite by reductive solid-state ion exchange, play an important role in the activation of hydrogen peroxide. The indium-hydroperoxo complex formed in beta zeolite pores was found to be accessible by the bulky cinnamyl alcohol molecules. Among the applied catalysts In/H[B]-beta (containing 7.6% In2O3/g) showed the highest selectivity in cinnamyl alcohol epoxidation.

Hydration of Unsaturated Hydrocarbons on Zeolite Catalysts

Abstract Catalysts containing Bronsted acid sites are active for hydration of 1-butene. The rate determining step is the surface reaction between 1-butene adsorbed in very small amounts and water adsorbed in larger amounts on hydrated protons which are presumably the active sites. Product 2-butanol exerts a competitive inhibition which can be suppressed by water. Zeolites containing late transition metal ions were found to catalyze the hydration of acetylene. This transformation is also kinetically controlled by the rate of the surface reaction between weakly adsorbed acetylene and rather strongly adsorbed water. Acetaldehyde bound to the active sites poisons the reaction reversibly. Its crotonic condensation which would result in a permanent poisoning can be avoided by the elimination of the acidic OH-groups generated by the electrostatic field of bivalent cations.