One Pot Synthesis of Cubic Mesoporous Silica KIT-6 Functionalized with Sulfonic Acid for Catalytic Dehydration of Fructose to 5-Hydroxymethylfurfural

Well-ordered cubic mesoporous silicas KIT-6 functionalized with sulfonic acid moiety (−SO₃H) (up to 30 mol% based on silica) are synthesized via co-condensation of tetraethoxysilane (TEOS) and mercaptopropyltrimethoxysilane (MPTMS) under acidic conditions using Pluronic P123 as the structure directing agent and H₂O₂ as the oxidant. The materials are used as heterogeneous catalysts for the dehydration of fructose to 5-hydroxymethylfurfural (HMF), and the HMF yield as high as 88 % is achieved at 135 °C within 40 min in the presence of dimethyl sulfoxide (DMSO) as solvent. The effects of various experimental parameters, such as reaction temperature, time, solvent, and the mass ratio of fructose to catalyst, on the HMF yield are also systematically investigated. The catalyst could be easily recovered from the reaction and reused, and 83 % HMF yield could be retained after used for three cycles, which demonstrated the remarkable stability of the catalyst.