【摘要】 研究了氧化石墨烯(GO)催化果糖-氯化胆碱低共熔物脱水制取5-羟甲基糠醛(5-HMF)的反应过程。采用改进的Hummers法制备GO,通过FT-IR、XRD和SEM等手段对GO结构进行了表征。考察了原料量、催化剂量、反应温度和时间等对5-HMF产物收率的影响。结果表明:果糖与氯化胆碱形成低共熔溶剂提高了果糖与GO的接触效率,脱水速率显著提高;在温度110℃,反应时间4h,GO与果糖质量比为1∶50的条件下,5-HMF液相色谱收率达到74. 5%,几乎没有检测到副产物。GO分子中的羧基基团担负着果糖的脱水过程。GO循环使用六次,仍具有较好的催化效果,5-HMF收率基本不变,说明GO重复使用性能良好。更多还原

【Abstract】 5-Hydroxymethyl furfural was synthesized from the catalytic dehydration of fructose-choline chloride deep eutectic solvent using a graphene oxide catalyst.Modified Hummers method was used for preparing graphene oxide( GO) and its structures were characterized using FT-IR,SEM and XRD.Deep eutectic solvent made from fructose and choline chloride improved greatly the contact efficiency between fructose molecules and graphene oxide catalyst.Effect of mass ratio of fructose to choline chloride,graphene oxide dosage,reaction temperature and time on the catalytic dehydration performances were investigated,respectively.Experimental results indicated that the required reaction time was shorted considerably in the presence of choline chloride,and the selectivity of desired product 5-HMF improved.Under the conditions of temperature 110℃,reaction time 4 h,mass ratio of GO to fructose of 1 ∶ 50,5-HMF liquid chromatography yield was up to 74. 5%,no byproducts were detected.It was suggested that the carboxylic acid group in GO was responsible for the dehydration of fructose.It was observed that after successive six runs,the activity and selectivity of the graphene oxide were almost unchanged.更多还原