Bifunctional Solid Catalysts for the Selective Conversion of Fructose to 5-Hydroxymethylfurfural

Solid catalysts based on SBA-15 silica were designed for the conversion of fructose to 5-hydroxymethylfurfural (HMF). The catalysts incorporate thioether groups that may promote the tautomerization of fructose to its furanose form, as well as sulfonic acid groups to catalyze its dehydration. The materials were characterized by elemental analysis, X-ray diffraction, N 2 adsorption/desorption, and solid-state 13 C and 29 Si CP/MAS NMR spectroscopy. Functional groups incorporated into mesoporous silica by co-condensation are more robust under the reaction conditions (water at 180 °C) than those grafted onto a non-porous silica. The bifunctional mesoporous catalyst achieved a selectivity for HMF of 74% at 66% fructose conversion.