Friedel-Crafts catalysis using supported reagents. Synthesis, characterization, and catalytic application of ZnCl2 supported on sol-gel-derived alumina

Alumina was synthesized by a sol-gel method using modifying agents such as 2,4-pentanedione, acetophenone, benzophenone, and dibenzoyl methane. The al umina supports were characterized employing N-2 adsorption studies and Al-2 7 solid-state NMR. The ZnCl2,/Al2O3 catalysts were made by impregnation of methanolic solution containing calculated amounts of ZnCl2 on modified alum ina supports. The influence of the loading of ZnCl2 and also the effect of additive used during the sol-gel synthesis of alumina, were probed using Fr iedel-Crafts alkylation reaction. The alkylation activities indicated the p redominance of pare volume in determining the catalytic activities of the c atalysts, rather than pore size distribution. (C) 2000 Elsevier Science B.V . All rights reserved.