Continuous flow synthesis of aldol condensation products from furfural using ternary hydrotalcites: Catalytic efficiency and selectivity

The development of highly sustainable processes for the efficient production of molecules of interest in the biofuel industry remains a topic of great significance. Aldol condensation reactions are fundamental in organic chemistry due to their ability to form carbon-carbon bonds, making them a key tool for synthesizing more complex molecules from simpler components. In this study, the aldol condensation reaction between furfural and acetone was investigated in a continuous-flow system using ternary hydrotalcites (LDH-MgCo and LDH-MgNi) and the mixed oxide LDO-MgCo. The catalytic activity of these materials depends on the basic sites present in each one. Weak basic sites in LDH-MgCo result in high selectivity toward the FC8 condensation product, while moderate and strong basic sites in LDH-MgNi and LDH-Mg (used as a control) promote the secondary reaction of acetone self-condensation. A similar behavior is observed in LDO-MgCo due to rehydration over time. Moreover, parameters such as pressure and temperature significantly affect the selectivity of the reaction. Under optimal conditions, this reaction system achieves a high conversion of furfural and excellent selectivity toward the FC8 product, along with remarkable catalyst stability. Over time, the formation of the FC13 product is also observed, a compound of notable interest in the biofuel industry. © 2025 Elsevier B.V., All rights reserved.