Abstract:
Nano TiO
2 gel and PEG-TiO
2 gel were synthesized with the sol-gel method and were used as catalysts for glucose conversion into 5-hydroxymethyl furfuraldehyde (HMF). The catalytic properties of nano TiO
2 gel and TiO
2 powder were compared. The results show that with nano TiO
2 gel as catalyst, the conversion rate of glucose into HMF was 93.7%, and the yield of HMF was 21.7% and with nano TiO
2 as catalyst, the glucose conversion rate was close to 100%, while the yield of HMF was only 1.4%. PEG-TiO
2 with higher gelid content of TiO
2 was prepared using polyethylene glycol (PEG 200) and ethyl titanate as raw materials, which was convenient for transportation, storage and use. Under the optimal conditions, with PEG-TiO
2 gel and formic acid as catalyst and water as reaction liquid, the glucose conversion rate reached 92.0%, the yield of HMF reached 56.2%, the reaction temperature was 100 ℃, and the reaction time was 12 h. The results provide a new method for large-scale green and efficient catalytic conversion of glucose into HMF in industry.