Bifunctionalized Mesoporous SBA-15: A New Heterogeneous Catalyst for the Facile Synthesis of 5-Hydroxymethylfurfural

Bifunctional porous nanomaterials are very demanding in the context of heterogeneous catalysis. A highly ordered 2D-hexagonal bifunctionalized mesoporous SBA-15 type material MPBOS (mesoporous bifunctionalized organosilica) has been synthesized via a post synthetic route. The surface of the SBA-15 has been functionalized with (3-chloropropyl)triethoxysilane to obtain MPCOS (mesoporous chloro-substituted organosilica) material, which undergoes an S N 2 substitution reaction of the surface a grafted chloro group with the amine group of organic ligand 5-aminoisophthalic acid, in the presence of potassium carbonate under refluxing conditions, offering the bifunctional material MPBOS. The bifunctionalized material with exceptionally high Brunauer–Emmett–Teller (BET) surface area of 652 m 2 g –1 and average pore diameter of 9.4 nm has been characterized thoroughly with powder X-ray diffraction (PXRD), N 2 sorption analysis, solid state 13 C cross-polarization magic angle spinning nuclear magnetic resonance (CP MAS NMR) spectroscopy, Fourier transform infrared (FT-IR), and UV–vis spectroscopy, high-resolution transmission electron microscopy (HR-TEM), field emission scanning electron microscopy (FE-SEM), thermogravimetric differential thermal analysis (TG/DTA), NH 3 temperature programmed desorption (NH 3 -TPD), and CHN analysis. The total acidity of this material has been determined from the NH 3 -TPD analysis, and this is estimated as 1.94 mmol g –1 . The acidic and basic sites present in this bifunctionalized material have been explored in catalytic conversion of abundant carbohydrates to hydroxymethylfurfural (HMF) with the highest yield of 74 mol % from fructose in organic polar solvent dimethyl sulfoxide (DMSO) under microwave assisted heating conditions.