Synthesis Of5-Hydroxymethylfurfural From Hexose Catalyzed By Polyoxometalate

Two solid acid catalyst are designed and synthesized by using different elements, and are applied in the heterogeneous acid-catalyzed reaction, then we investigate that the catalytic activity of the catalysts catalyze fructose dehydration to5-hydroxymethylfurfural (5-HMF) in DMSO (dimethyl sulfoxide) system. In addition, we discuss some possible influencing factor, such as amount of catalyst, reaction time, the concentration of fructose, reaction temperature, the usage of DMSO and the recycle of catalyst. Low selectivity, the corrosion of equipments and other problems in the acid-catalyzed fructose dehydration to HMF are solved. Moreover, in the field of expoliting new and efficient catalysts, the result of the paper has a certain economic and theoretical value. The main results are shown as follows:1. PW12O403-anion was immobilized on the meso-ZrO2by protonation to obtain the acid catalyst PWt2O40@meso-ZrO2, then the catalyst was characterized by IR, ICP-AES and so on. The maximam value94.2%of yield of HMF was obtained in the conversion of fructose to5-HMF in DMSO reaction system at120℃for60min by using0.05g of PW12O40@meso-ZrO2as catalyst, and the concentration of fructose was3wt%. The catalyst PW12O40@meso-ZrO2was obtained by centrifuge, then washed with water and dried at80℃for3h under atmosphere of nitrogen, and reused. The results showed that catalyst PW12O40@meso-ZrO2can reused and was a environmentally benign, water-tolerant acid catalyst.2. PW12O403-anion was immobilized on the meso-TiO2by ion exchange to obtain the acid catalyst PW12040@meso-TiO2, then the catalyst was characterized by IR, ICP-AES and so on. The maximam value84.2%of yield of HMF was obtained in the conversion of fructose to5-HMF in DMSO reaction system at120℃for60min by using0.05g of PW12O40@meso-TiO2as catalyst, and the concentration of fructose was3wt%. The catalyst PW12040@meso-TiO2was obtained by centrifuge, then washed with water and dried at80℃for3h under atmosphere of nitrogen, and reused. The results showed that catalyst PW12040@meso-TiO2can reused and was a environmentally benign, water-tolerant acid catalyst.