One-pot aerobic conversion of fructose to 2,5-diformylfuran using silver-decorated carbon materials

The synthesis of 2,5-diformylfuran (DFF) from fructose is a simultaneous process using two distinct catalysts, including fructose dehydration to 5-hydroxymethylfurfural (5-HMF) accelerated by an acid catalyst, followed by 5-HMF oxidation to DFF mediated by a redox catalyst. In this study, various catalysts with Ag metal decorated on sulfonated amorphous carbon supports (AC-SO3H@Ag) were performed, and their structures were characterized via different characterization techniques such as X-ray diffraction, scanning electron microscopy, X-ray fluorescence spectroscopy, thermogravimetric analysis, Boehm's titration, inductively coupled plasma mass spectroscopy, energy-dispersive X-ray spectroscopy, elemental mapping analysis and Fourier-transform infrared spectroscopy. The catalytic performance of the prepared AC-SO3H@Ag bifunctional catalysts with various wt% of Ag/AC-SO3H was determined for the one-pot transformation of fructose into DFF. The influence of solvent, substrates, reaction time, and catalyst loading were also examined thoroughly to optimize the reaction, and a mechanism was proposed. 5-HMF formed by the dehydration of fructose was converted entirely to DFF, and the highest DFF yield of 77.9 % was obtained after 18 h of reaction time at 150 °C in dimethyl sulfoxide with 3 wt% of the AC-SO3H@Ag catalyst and without the use of any additives, traditional hydrogen acceptors, or oxidants. The reusability of the catalysts was also tested.