Acetalization of glycerol with acetone over UAV-59 catalyst: Mild reaction conditions and enhanced selectivity

Abstract

The solvent-free acetalization of glycerol with acetone was investigated using as catalyst UAV-59, a Coordination Polymer based on nitrilo(trimethylphosphonic acid) and Gd3+, at 25 °C and 55 °C, with various glycerol/acetone (Gly/Ace) molar ratios. The reaction yielded solketal, a five-membered acetal, and 2,2-dimethyl-1,3-dioxan-5-ol, a six-membered acetal. UAV-59's catalytic activity was influenced by temperature, with the highest conversion (94%) achieved at 55 °C, a 1/10 Gly/Ace ratio, and 5% catalyst. The selectivity for solketal remained consistent (95–98%) across all conditions. Reaction kinetics and selectivity profiles were compared, catalyst stability was assessed, and results were benchmarked against Metal Organic Framework catalysts from the literature. The heterogeneous nature of catalysis was confirmed through leaching tests, and the catalyst's chemical features were analyzed using ATR FT-IR spectra and X-ray diffraction patterns, indicating that UAV-59's crystalline structure was preserved during the reaction.