Design Of New Solid Acid Catalyst And Study On Fructose One-pot Preparation Of 5-hydroxymethylfurfural

Biomass,as an alternative to fossil fuels,has great potential to provide sustainable energy production for the future of mankind.Biofuels produced from cellulosic biomass are recognized as promising alternatives due to their low cost,abundance and sustainability.5-Hydroxymethylfurfural(5-HMF)is listed as one of the top ten biochemical products produced from biomass,which is mainly produced by dehydration of sugars.Studies have shown that the conversion efficiency of fructose catalyzed synthesis of 5-HMF is higher than that of other sugars.Acids can promote the degradation of sugars into hydroxymethylfurfural,furfural and other products.Due to their low cost,strong stability and environmental friendliness,solid acid catalysts for biomass conversion have received more and more attention.Based on the above background,this thesis focuses on the preparation of solid acid catalysts and their use in fructose dehydration to prepare5-hydroxymethylfurfural.The following aspects of work are carried out:In the first part,after preparing mesoporous silica supports by hydrothermal method,Tf OH-MSNSs solid acid catalysts were synthesized by post-grafting method,which utilizes the high acidity of sulfonic acid groups to promote fructose dehydration.The catalyst can promote the dehydration process and improve the selectivity of the product.The conversion rate of 89 % and the selectivity of 88 %are achieved at 120 ?,0.5 h,and 10 mg,which is better than the commercial catalyst Amberlyst-15.In the second part,the sulfonic acid-type COF catalyst was synthesized by solvothermal method,and the catalyst dosage and reaction conditions were adjusted to explore the effect on the catalytic performance.It is found that the catalytic activity is good,and it is easy to recycle and has good stability.Finally,the kinetics and activation energy of fructose dehydration reaction were discussed according to the catalytic activity at different temperatures and times.It is concluded that the fructose dehydration reaction kinetics conform to the first-order kinetic model,and the addition of solid acid catalyst reduces the reaction activation energy and promotes fructose conversion.