Direct synthesis of metal-organic frameworks catalysts with tunable acid–base strength for glucose dehydration to 5-hydroxymethylfurfural

Developing a green and economically viable approach for the direct synthesis of metal-organic frameworks (MOFs) catalysts with multifunctional active sites remains the key step for their applications in heterogeneous catalysis field. Herein, we report a green (aqueous solutions), mild (90 °C, atmospheric pressure), and modulated hydrothermal (MHT) approach to synthesize UiO-66-type MOFs catalysts with acid–base bi-functional sites, which were obtained via the coordination of monosodium 2-sulfoterephthalate and 2-aminoterephthalic with zirconium (Zr) ions. More importantly, a series of acid, base and acid–base catalysts with varied acid–base strengths can be readily prepared, by simply varying the ratio of organic ligands for preparing MOFs. The synthesized catalysts were characterized and their performances in glucose dehydration to produce 5-hydroxymethylfurfural (5-HMF) have been evaluated. The developed approach in this work has clearly depicted a roadmap for the facile synthesis of MOFs catalysts to facilitate their potential use in acid–base catalysis.