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首页|期刊导航|燃料化学学报(中英文)|改性锡丝光沸石催化混合糖脱水制备5-羟甲基糠醛

改性锡丝光沸石催化混合糖脱水制备5-羟甲基糠醛OA北大核心CSTPCD

Dehydration of sugar mixtures to 5-hydroxymethylfurfural catalyzed by modified tin-mordenite

中文摘要英文摘要

采用酸处理脱铝补位两步法对丝光沸石(MOR)锡改性制备了系列Sn-MOR催化剂,用X射线衍射(XRD)、紫外-可见漫反射光谱(UV-vis)、氨程序升温脱附(NH3-TPD)、X射线荧光光谱(XRF)对其进行表征.结果表明,改性后催化剂仍保持丝光沸石的晶体结构,酸中心强度与酸量有改变,同时在沸石骨架中引入了锡.研究了改性丝光沸石催化单糖(葡萄糖、果糖)及混合糖生成 5-羟甲基糠醛(HMF),结果表明,改性后的Sn-MOR仍保持MOR对果糖脱水为HMF的较高催化活性,同时引入的锡物种对葡萄糖具有异构化活性,因此,Sn-MOR可以同时催化葡萄糖和果糖脱水生成HMF.以商品果葡糖浆作为反应底物,在果葡糖浆质量 1.94 g,催化剂用量 0.3 g,反应温度 170℃,反应时间 3h的较优反应条件下,以3.76-Sn-MOR1 为催化剂,果葡糖浆转化率 91.82%,HMF产率 63.76%,HMF选择性 69.43%;催化剂循环使用五次,仍保持了一定的催化活性,HMF产率仍有 49.5%.

5-hydroxymethylfurfural(HMF)is a versatile compound that has great market potential in the future chemical industry.HMF production from fructose has a problem of higher cost,while HMF production from glucose has a problem of lower yield.Therefore,the use of relatively inexpensive biomass-derived syrup to produce HMF in order to achieve industrial production is currently a research hotspot.A series of Sn-MOR catalysts were prepared by using mordenite zeolite(H-MOR)as a carrier,which was modified with acid treatment and adding tin to remove Al and replenish Sn.The Sn-MOR catalysts were characterized by X-ray diffraction(XRD),diffuse reflectance ultraviolet-visible spectra(UV-vis),ammonia temperature programmed desorption(NH3-TPD),and X-ray fluorescence spectroscopy(XRF).The characterization results showed that the Sn-MOR still maintained the crystal structure of mordenite,with changes in strength and content of acid centers,and Sn was inserted into the zeolite skeleton.Glucose and fructose were used as substrates in the catalytic reaction of unmodified H-MOR and modified Sn-MOR,and the experimental results showed that H-MOR catalyzed the dehydration reaction of glucose poorly,with a HMF yield of only 7.08%,but its catalytic performance in dehydration of fructose was better,with a HMF yield of 76.78%.The modified Sn-MOR possessed isomerization activity,which improved the reactivity of glucose dehydration with a HMF yield of 38.65%,while the modified Sn-MOR still maintained the high catalytic activity of MOR for fructose dehydration to HMF.Using sugar mixtures(mhydrated glucose∶mfructose=1∶1)as the substrate,the reaction performance of the catalysts with different tin metal additions to H-MOR was firstly investigated,and the results showed that 3.76-Sn-MOR with 3.76%tin addition catalyzed the dehydration of the sugar mixtures better.The reaction performance of the catalyst prepared by adding tin after H-MOR acid treatment was further investigated,and the results showed that the 3.76-Sn-MOR1 prepared by acid treating H-MOR using 1 mol/L hydrochloric and adding tin could obtain better HMF yield(49.37%)and selectivity(58.09%)in dehydration of sugar mixtures.The reaction conditions were further optimized through orthogonal experiments using a 3.76-Sn-MOR1 catalyst in terms of sugar concentration,reaction temperature,catalyst dosage,and reaction time.The results showed that neither too high nor too low sugar concentration was conducive to HMF formation,and increasing temperature and catalyst dosage were conducive to HMF formation,but increasing temperature reduced the selectivity of HMF.Prolongating reaction time had little effect on improving the yield of HMF,but decreased the selectivity of HMF.The optimal reaction conditions were as follows:1.5 g of sugar mixtures,reaction temperature of 170℃,catalyst dosage of 0.3 g,and reaction time of 3 h.Under the above optimal reaction conditions,the superior catalyst 3.76-Sn-MOR1 was finally applied to F55 fructose syrup,which has a dry matter ratio of glucose and fructose similar to that of sugar mixtures,and the HMF yield was 63.76%,the HMF selectivity was 69.43%,and the fructose syrup conversion was 91.82%.The catalyst was recycled five times and the HMF yield reduced to 49.50%,which still maintained a certain catalytic activity.

张若楠;李钢;麻忠敏;吕强

大连理工大学化工学院精细化工国家重点实验室,辽宁大连 116024青岛三力本诺新材料股份有限公司,山东青岛 266000

化学

混合糖5-羟甲基糠醛锡-丝光沸石脱铝补位脱水反应

sugar mixtures5-hydroxymethylfurfuraltin-mordenitede-Al-substitutiondehydration reaction

《燃料化学学报(中英文)》 2024 (008)

1070-1078 / 9

10.19906/j.cnki.JFCT.2024018

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