An Experimental and Theoretical Study on the Aldol Condensation on Zirconium-Based Metal-Organic Framework

摘要

The aldol condensation of acetone in zirconium-based metal-organic framework functionalized by a sulfonic acid group (UiO-66-SO_3H) has been theoretically investigated using the density functional theory. Acetone adsorbed on the UiO-66-SO_3H with the adsorption energy of -17.4 kcal/mol. The catalyzed reaction has been proposed to be a two-step mechanism: the tautomerization of keto form to produce enol form of acetone, and the aldol condensation to produce diacetone alcohol. The activation energies were calculated to be 27.2 and 6.4 kcal/mol, respectively. For the experimental part, UiO-66-SO_3H catalyst was synthesized and characterized by X-ray diffraction and IR spectroscopy. The catalytic reaction was carried out in a stirred batch reactor at different temperatures to optimize the reaction conditions. The obtained products were analyzed by ~1H-NMR spectroscopy and chromatography techniques. This study demonstrated that UiO-66-SO_3H can be used as a solid catalyst for the aldol condensation reaction.