Synthesis of a Solid Base Catalyst Formed from Zinc(II) Acetylacetonate and Consisting of MgO Modified with ZnO

Abstract

Solid base catalysts consisting of MgO modified with 10 mol% ZnO (ZnO/MgO) were prepared by depositing zinc(II) acetylacetonate (Zn(acac)2) in polar and nonpolar organic solvents on the surface of MgO and Mg(OH)2. The process was followed by thermal decomposition in air at 773 K over a period of 3 h. The activity of MgO modified with Zn(acac)2 for base-catalyzed retroaldol reaction (the decomposition of diacetone alcohol (4-hydroxy-4-methyl-2-pentanone) to acetone) at 299 K was higher than the activity of unmodified MgO prepared by thermal decomposition of Mg(OH)2. The activity of the catalysts prepared by depositing Zn(acac)2 on Mg(OH)2 was lower than that of unmodified MgO. Analysis of X-ray diffraction patterns revealed the presence of highly intense peaks, which were assigned to the ZnO units in the samples with high catalytic activity. ZnO was deposited in the form of large particles on the surface of MgO in the catalysts with high activity.