Synthesis Of Functional Graphene For Conversion Of Monosaccharide

Fossil energy can be replaced by biomass energy in the future, which is regarded as a good choice. Biomass energy has many advantages, such as richness, cleanability and renewability. The development of biomass energy can effectively overcome the inadequate storage and serious pollution caused by fossil energy. Cellulose is abundant biomass resources, but it is difficult to dissolve and degrade because of the presence of many hydrogen bonds. Compared with cellulose, glucose can be degraded easily because glucose is monomer. What is more, the degradation of monosaccharide is the key step during the transformation of cellulose to platform compound. In this article,the monosaccharide is used as substrate for experiments.In recent years, graphene has attracted much attention due to its excellent physical and chemical properties. The surface of graphene oxide includes oxygen-containing functional groups, such as hydroxyl, carboxyl and epoxy groups. The existence of these groups will greatly promote its solubility in water and makes it possible for the synthesis of functionalized graphene. The synthesis of functionalized graphene contains covalent and non covalent bond. In this article, two methods are used to prepare two kinds of catalysts, and its catalytic activity are studied.In Chapter Ⅱ, rGO-SO3H was synthesized by using propane sultone and sodium hydride(NaH).Here, propane sultone was used as sulfonated reagent and sodium hydride(NaH)was used as reducing agent. FT-IR,TGA,XPS,SEM,TEM and elemental measurements suggest that the sulfonic acid groups were grafted successfully to the surface of graphene. The as-prepared catalyst was used in the reaction of glucose degradation. The influence of catalyst concentration, reaction temperature and reaction time on the glucose hydrolysis were studied to explore the most suitable reaction conditions. The optimal reaction conditions were obtained: glucose/catalyst=8, temperature:200℃, time:2h, H2O:20ml. The yields of formic acid, lactic acid and HMF were15.39%,7.75%and28.8%respectively when the reaction of glucose degradation was conducted at the most suitable reaction condition. The total yield of three kinds of product is51.94%. The solid acid catalyst still shows a relatively higher reaction activity after five run experiments, suggesting that it has good thermal stability. In Chapter Ⅲ,The WO3@GO was synthesized by using a simple sonochemical method, and the phosphotungstic acid was used as the source of the WO3nano-particles. The new catalyst was analyzed by using FT-IR and TEM. The result of FT-IR of the new material reveal that the sulfonic acid groups have been existed on the surface of graphene. In addition, the TEM image of W03@GO indicates that the WO3nano-particles have a uniform distribution on the surface of graphene. In order to find the optimal reaction condition, the reaction of hydrolysis of glucose was conducted at different experiment parameter (reaction temperature, reaction time and catalyst dosage).The optimum conditions of reaction was as follows: fructose/catalyst=8, temperature:160℃, time:2h, H2O:20ml. The total yield of five kinds of product is43.25%.