Hydrotalcite-supported palladium catalysts Part II. Preparation, characterization of hydrotalcites and palladium hydrotalcites for CO chemisorption and phenol hydrogenation

Hydrotalcites and hydrotalcite-like compounds, having Zn2+ and Li+ as brucite layer cations are prepared. They are tested as supports to disperse palladium and for selective hydrogenation of phenol to cyclohexanone. The hydrotalcite materials and palladium catalysts are characterized by XRD, IR, DTA, BET surface area and CO uptake measurements. Calcination temperature and the aluminium content of the hydrotalcite were found to affect the palladium dispersion and deactivation in phenol hydrogenation. Hydrotalcite having Li+ in the brucite-like layer was found to be a good support for dispersion of Pd and phenol hydrogenation activity. However, it is not selective for cyclohexanone. (C) 2000 Elsevier Science B.V. All rights reserved.