Structure activity relationship in Pd/hydrotalcite: effect of calcination of hydrotalcite on palladium dispersion and phenol hydrogenation

Hydrotalcites (HTs) are prepared by low supersaturation and high supersatur ation methods containing Mg2+ and Al3+ cations in the brucite-like sheets a nd having interlayer CO32- anions. Pd/HT with Pd2+ in the brucite layer was also prepared for comparison. Catalysts containing I wt% of Pd are prepare d by impregnation method using different Pd precursors. HT and Pd on HT sam ples are well characterised by XRD and surface area analysis. CO chemisorpt ion is used to estimate the dispersion and metal area of Pd. The supported metal catalysts are evaluated for phenol hydrogenation. Metal dispersion an d catalytic activity depend on the calcination temperature of the HT suppor t. (C) 1999 Elsevier Science B.V. All rights reserved.