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凹土(ATP)有“千用之土、万土之王”之美誉,我国江苏省盱眙凹土矿资源量占世界储量的49%和我国储量的74%.ATP是一种天然链层状结构的含水镁铝硅酸盐黏土矿物,其分子式为(Mg,Al)4(Si)_8(O,OH,H_2O)_(26)·nH_2O.ATP具有一定酸性,层结构中的结构羟基可形成Br?nsted酸位点,暴露的Al~(3+)离子可形成Lewis酸位点.ATP经酸化或离子交换后作为催化剂直接应用较少.由于ATP具有较大的比表面积和较好的热稳定性,是良好的催化剂载体,因此多将ATP作为载体负载催化活性组分制备负载型催化剂.5-羟甲基糠醛(HMF)是由生物质得到的十二种平台化合物之一,是非常重要的中间体,可用于生产呋喃类衍生物,制备精细化学品、液体燃料和多种聚合物,还可生产5-羟基-4-酮-2-戊烯酸和乙酰丙酸.γ-戊内酯(GVL)是一种乙酰丙酸的加氢产物,可以代替乙醇作为汽油添加剂,也可用来生产丁烯同分异构体等化学品.本文以天然ATP为载体,通过浸渍-焙烧法设计和制备了兼具Br?nsted酸和Lewis酸的新型固体酸催化剂SO_4~(2-)/In_2O_3-ATP.该催化剂可催化己糖直接转化为HMF.ATP固有的微观结构和高比表面积使反应选择性提高.同时,结合固体酸活性位表征技术探索了己糖转化历程和HMF生成机制.结果表明,In(III)的引入使ATP催化性能更加优越.固体酸的Lewis酸位和Br?nsted酸位能分别有效催化葡萄糖异构和果糖脱水.优化的最佳反应条件为:GVL:H_2O双相体系比例9:1,反应温度180oC,反应时间60min.底物为葡萄糖时,HMF最高收率为40%.SO_4~(2-)/In_2O_3-ATP固体酸比纯ATP酸性更强,可重复使用4次,且不腐蚀设备,后处理简单,绿色环保.
ATP has the reputation of “the land of thousands of uses and the king of all earths”, and the resources of the Qionglai sunken earth in our province occupy 49% of the world’s reserves and 74% of China’s reserves. ATP is a kind of natural chain The layered magnesium aluminosilicate clay mineral has the formula (Mg, Al) 4 (Si) 8 (O, OH, H 2 O) _ (26) · nH 2 O.ATP has a certain acidity and the structure in the layer structure Brønsted acid sites can be formed by hydroxyl groups, and Lewis acid sites can be formed by exposed Al ~ (3+) ions.ATP can be directly used as a catalyst after acidification or ion exchange, which is less.As ATP has a large specific surface area Good thermal stability, is a good catalyst carrier, ATP is therefore used as a supported catalyst for the preparation of active catalyst-loaded catalyst.5-hydroxymethylfurfural (HMF) is one of the twelve platform-derived compounds obtained from biomass , Is a very important intermediate for the production of furan derivatives, fine chemicals, liquid fuels and a wide range of polymers. It also produces 5-hydroxy-4-keto-2-pentenoic acid and levulinic acid. Gamma-valerolactone (GVL), a hydrogenated product of levulinic acid, can replace ethanol as a gasoline additive and can also be used to produce isobutene In this paper, a new solid acid catalyst, SO 4 2- / In 2 O 3 -ATP, which has both Brønsted acid and Lewis acid, was designed and prepared by impregnation-roasting method using natural ATP as carrier. And transformed into HMF.The inherent microstructure and high specific surface area ofATP enhanced the reaction selectivity.At the same time, the mechanism of hexose conversion and HMF formation were explored in combination with the solid acid active site characterization technique.The results showed that the introduction of In (III) The catalytic performance is more superior.The solid acid Lewis acid sites and Br? Nsted acid sites can effectively catalyze the glucose isomerization and fructose dehydration respectively.The optimal reaction conditions are as follows: the ratio of GVL: H 2 O biphasic system is 9: 1, the reaction temperature is 180oC , The reaction time was 60min.The maximum yield of HMF was 40% when the substrate was glucose.SO_4 ~ (2 -) / In_2O_3-ATP solid acid was more acidic than pure ATP and could be reused for 4 times, Simple processing, green environmental protection.