Abstract:
A bifunctional carbon-based solid acid catalyst was prepared by sulfonation of sulfuric acid to using gelatin and phytic acid (PA) as carbon sources and doping with FeCl
3·6H
2O and ZnCl
2, which was used to efficiently catalyze the preparation of furfural from xylose. The catalysts prepared at different carbonization temperatures were characterized by SEM, BET, FT-IR and STEM-EDS techniques, and the physicochemical properties of the catalysts were revealed. The effects of carbonization temperature of the catalyst, molar ratio of FeCl
3·6H
2O to ZnCl
2, reaction temperature, reaction time, volume ratio of γ-valerolactone (GVL) to H
2O and catalyst dosage on the conversion of xylose to furfural (FF) were investigated. The results showed that the catalytic activity of CNPS600-Fe
4-Zn
2 was higher when the carbonization temperature was 600 ℃. The xylose conversion rate was 99.6%, and the molar yield of FF reached 85.8% when the reaction was carried out at 170 ℃ for 120 min using 0.03 g CNPS600-Fe
4-Zn
2 (the molar ratio of FeCl
3·6H
2O to ZnCl
2 was 4∶2) as catalyst, 3 mL GVL/H
2O (the volume ratio of was 9∶1) as solvent and 0.06 g xylose as raw material. In addition, the cyclic performance of the catalyst was tested. The FF molar yield and xylose conversion rate remained above 80% after 5 cycles, indicating that the catalyst had higher catalytic activity and better hydrothermal stability.