2-Hydroxymethylfurfural (HMF) Was Synthesized By The Oxidation Of Monosaccharides By Metal Oxide Solid Acid

5- hydroxymethyl furfural(HMF) is one of the most important biochemical raw materials, Monosaccharide conversion preparation 5- hydroxymethyl furfural reaction is an important link of biomass utilization. In the traditional process, The problem of serious corrosion of equipment, complex post treatment, environmental pollution were existed when using the homogeneous acid catalyzed monosaccharide conversion to HMF. Therefore, focusing on conversion of biomass by “green catalyst” was made in this paper, which is shown as follows.(1) In this paper, B2O3-ZrO2 solid acid catalyst was prepared by the method of template and ultrasonic system from Zirconium n-propoxide and boric acid through an evaporation-induced self-assembly(EISA) process. The different proportion(Zr:B=1:0, 1:0.5,1:1, 1:1.5) of catalysts were screened and selected the optimal catalyst ratio(Zr:B=1:1). The catalysts were characterizated by FTIR, XRD, SEM, NH3-TPD etc, which indicate the catalyst was successfully synthetized. The optimal catalyst was used to catalyze glucose conversion to HMF. A variety of factors that affect reaction such as reaction time, reaction temperature, substrate concentration, different solvents were investigated. Finally 17.6% yield of HMF was obtained under the optimum reaction condition, 50 mg glucose, 20 mg catalyst, 1.0 g DMSO, 160 ℃, 180 min.(2) B2O3-WO3 solid acid catalyst was prepared by the method of template and ultrasonic system from WCl6 and boric acid through an evaporation-induced self-assembly(EISA) process. The different proportion(W:B=1:0, 1:1,1:2, 1:3) of catalysts were screened and selected the optimal catalyst ratio(W:B=1:1). The catalyst were characterizated by FTIR, XRD, SEM, NH3-TPD etc, which indicated the catalyst was successfully synthetized. The optimal catalyst were used to catalyze glucose conversion to HMF. A variety of factors that affect reaction such as reaction time, reaction temperature, substrate concentration, different solvents were investigated. The yield of HMF was 15.6% under the optimum reaction condition, which are 50 mg glucose, 20 mg catalyst, 0.8 g DMSO, 160 ℃, 180 min.(3) A series of nano-sized mesoporous Al2O3-B2O3 catalysts with different molar ratios of Al/B were prepared from aluminum isopropoxide and boric acid through an evaporation-induced self-assembly(EISA) process, and were characterized by ICP-AES, FTIR(pyridine adsorption), XRD, NH3-TPD, SEM, TEM, and N2 adsorption-desorption. These catalysts were further used as solid acids in the catalytic conversion of glucose to HMF. An optimized HMF yield of 41.4% was obtained within 120 min at 140 oC over Al2O3-B2O3(Al/B=5:5). It was demonstrated that catalysts with the presence of Lewis acid sites were more favorable for the formation of HMF.