Study On The Catalysts For Dehydration Of Glucose To 5-HMF

With the development of society,the demand for energy increase day by day.Biomass energy,which is a renewable energy source,has gradually gain attention.The continuous and efficient conversion of glucose into chemicals has become a research hotspot.However,it’s a big challenge that continuously converse glucose into high value-added chemicals in the aqueous phase.We studied that how the composition of acidic sites effect on the product distribution in glucose dehydration reaction,and provided a new idea of catalysts design for glucose dehydration to 5-HMF in aqueous phase.In this work,we studied the activity of traditional Zr O₂ support in glucose dehydration continuously in the aqueous phase.We found that in245℃and 5 MPa H₂,100%glucose conversion and 65.8%carbon molar selectivity of 5-HMF were obtained.XRD,XPS,NH₃-TPD,DRIFT,and Py-FTIR showed that the high activity of the reduced catalyst was due to the strong acidity.Then,we used metal oxide promoters and adjusted its loading,and found 1Sn O₂/Zr O₂ catalyst was the best,with glucose conversion 100%and a carbon molar selectivity of 74.1%for 5-HMF.XRD,XPS,NH₃-TPD and Py-FTIR showed that the appropriate acid site ratio L/B on the catalyst surface effected on the carbon molar selectivity of5-HMF.In this system,L/B=18.7 was the best condition for the highest carbon molar selectivity of 5-HMF.In addition,we studied the activity of a new type material Ti₃AlC₂catalyst in the dehydration of glucose.Then,we used metal oxide promoters and adjusted its loading,and we found 3Cr₂O₃/Ti₃AlC₂ catalyst was the best option,with glucose conversion 100%and the carbon molar selectivity of 5-HMF 76.5%in 205℃and 2 MPa H₂ pressure.XRD,XPS,NH₃-TPD,H₂-TPR and Py-FTIR showed that the introduced active sites interacted with the supporter,which changed the distribution of acidic species on the surface,and adjusted the L/B value of the catalyst surface.In this system,5-HMF had the highest carbon molar selectivity when L/B=1.1.