基于质子型离子液体微介孔硅材料的制备及性能研究

发布时间：2018-06-09 03:41

本文选题：微介孔 + 硅材料　；参考：《东南大学》2015年硕士论文

【摘要】：微孔分子筛具有较小的孔径、较大的比表面积、较好的水热稳定性等特点,而被广泛地应用到催化、吸附和分离等领域,但是,较小的孔道结构阻碍了反应物和产物的扩散和吸附,从而限制了其在大分子反应中的应用。与微孔分子筛相比,介孔分子筛具有较大的孔径和较厚的孔壁,能够在一定程度上弥补微孔分子筛的缺点,可以用于催化大分子的反应,但介孔分子筛的水热稳定性较差,限制了介孔分子筛的进一步发展。由于单级孔材料都有其各自的优缺点,迫切需要制备具有多种孔结构的新型材料,这种多级孔材料不仅具有多种孔道结构,而且具有较大的比表面积和孔容,从而能够提高分子筛的性能。二芳基乙烷(PXE)是压敏复写纸显色剂的优良溶剂,主要通过邻二甲苯和苯乙烯的烷基化反应获得。本论文以P123和质子型离子液体为双模板剂,以正硅酸四乙酯(TEOS)为硅源,一步水热法制备了微介孔二氧化硅材料,以此为载体负载磷钨酸(HPW)制备了负载型催化剂,并用邻二甲苯和苯乙烯合成PXE的烷基化反应来考察催化剂的催化活性。采用质子型离子液体醋酸三乙胺(CH3CH2)3NH+Ac微孔模板剂及P123介孔模板剂的双模板体系,TEOS为硅源,一步水热法制备了微介孔二氧化硅材料PIL-X-Y,考察了离子液体质量占总模板剂质量的百分比(X)、晶化温度(Y)对PIL-X-Y结构的影响。研究表明：当离子液体含量较低时,微介孔材料的结构有序度较高；随着离子液体用量的加大,其有序的结构遭到破坏。当X为40%,Y为373 K时,制备的微介孔硅材料PIL-40-373不仅能够保持有序介孔结构,而且还具有较大的微孔比表面积,其微孔比表面积为404 cm2.g-1。在烷基化反应中,与SBA-15为载体负载HPW得到的催化剂HPW/SBA-15相比,以微介孔硅材料PIL-X-Y为载体负载HPW制备的催化剂HPW/PIL-X-Y的催化性能较好,PXE产率大于80%,这可能与PIL-X-Y的微孔结构有关。以质子型离子液体醋酸丁胺CH3CH2CH2CH2NH3+Ac和P123分别作为微孔和介孔的模板剂,TEOS为硅源,一步水热法制备了具有双介孔的微介孔二氧化硅材料BPIL-X-Y,考察了离子液体质量占总模板剂质量的百分比(X)、晶化温度(Y)对BPIL-X-Y结构的影响。研究表明：BPIL-X-Y具有双介孔孔道结构,其孔径分别为4.0 nm、7.3 nm,且这两种介孔分别由离子液体胶束和P123胶束引导产生。以BPIL-X-Y为载体负载HPW制备的负载型催化剂HPW/BPIL-X-Y在烷基化反应中,表现出了较高的催化活性,PXE的产率最高可达91%,并且多次使用后还能保持较好的催化性能,这可能与载体BPIL-X-Y独特的双介孔结构和微孔孔道结构有关。当离子液体(CH3CH2)3NH+Ac"质量占总模板剂质量的百分比为60%,以P123为介孔模板剂,TEOS为硅源,进一步考察了晶化温度(Y)、pH(Z)和超声辅助方法对微介孔硅材料HAM-Y-Z形成的影响。研究表明：当pH为2时,制备了具有双介孔的微介孔硅材料HAM-393-2；当pH为3时,制备出了泡沫介孔硅材料HAM-393-3。烷基化反应表明：以具有较大介孔的HAM-393-3为载体负载HPW制得的催化剂HPW/HAM-393-3的催化活性最高,PXE产率为95%,这可能与载体的比表面积和孔径大小有关,并且较大的孔径有利于烷基化反应。综上所述,采用P123和质子型离子液体为双模板剂制备的微介孔硅材料具有较高的比表面积、较大的孔径、独特的孔道结构,这些优点使得微介孔硅材料能够作为催化剂载体应用于烷基化反应中。
[Abstract]:Microporous molecular sieves have the characteristics of smaller pore size, larger specific surface area and better hydrothermal stability, and are widely used in the fields of catalysis, adsorption and separation. However, the smaller pore structure hinders the diffusion and adsorption of reactants and products, thus limiting its application in large molecular reactions. Compared with microporous molecular sieves, Mesoporous molecular sieves, with large pore size and thicker hole wall, can make up the shortcomings of microporous molecular sieves to a certain extent, and can be used to catalyze the reaction of large molecules. However, the hydrothermal stability of mesoporous molecular sieves is poor, which limits the further development of mesoporous molecular sieves. A new type of material with a variety of pore structure has been prepared. This multilevel porous material not only has a variety of pore structure, but also has a large specific surface area and Kong Rong, which can improve the performance of the molecular sieve. Two aryl ethane (PXE) is a good solvent for the pressure-sensitive compound paper color reagent, which is mainly obtained by alkylation of phthalene and styrene. In this paper, P123 and proton type ionic liquids were used as a double mode plate and four ethyl orthosilicate (TEOS) as the silicon source. Micro mesoporous silica materials were prepared by one step hydrothermal method. As a carrier Supported Phosphotungstic Acid (HPW), a supported catalyst was prepared. The catalytic activity of the catalyst was investigated by the alkylation of o-xylene and styrene into PXE. The proton type ionic liquid acetate three ethylamine (CH3CH2) 3NH+Ac microporous template and P123 mesoporous template system, TEOS as the silicon source, were used to prepare the micro mesoporous silica material PIL-X-Y by one step hydrothermal method. The effects of the mass percentage (X) of the ionic liquid mass to the total template mass (X) and the crystallization temperature (Y) on the structure of PIL-X-Y were investigated. The results showed that the effect of the crystallization temperature (Y) on the structure of PIL-X-Y was investigated. When the content of ionic liquid is low, the structure of micro mesoporous material is more ordered. With the increase of ionic liquid, the ordered structure is destroyed. When X is 40% and Y is 373 K, the micro mesoporous silicon material PIL-40-373 can not only maintain the ordered mesoporous structure, but also have a larger micropore specific surface area, and its micropore ratio table The area of 404 cm2.g-1. is in the alkylation reaction, compared with the catalyst HPW/SBA-15 obtained by SBA-15 as the carrier load HPW, the catalytic performance of the catalyst HPW/PIL-X-Y prepared with the microporous silicon material PIL-X-Y as the carrier load HPW is better, the PXE yield is greater than 80%, which may be related to the micropore structure of PIL-X-Y. H3CH2CH2CH2NH3+Ac and P123 as a template for microporous and mesoporous and TEOS as the silicon source, a micro mesoporous silica material with double mesoporous BPIL-X-Y was prepared by one step hydrothermal method. The effect of the mass of ionic liquid on the mass of the total template (X) and the crystallization temperature (Y) on the structure of BPIL-X-Y was investigated. The study showed that BPIL-X-Y had a double medium. The pore pore structure is 4 nm and 7.3 nm respectively, and the two kinds of mesoporous pores are produced by ionic liquid micelles and P123 micelles respectively. The supported catalyst HPW/BPIL-X-Y, prepared with BPIL-X-Y as the carrier HPW, shows high catalytic activity in the alkylation reaction, and the yield of PXE is up to 91% and can be used for many times. It is possible to maintain good catalytic performance, which may be related to the unique double mesoporous structure and pore structure of the carrier BPIL-X-Y. When the mass of ionic liquid (CH3CH2) 3NH+Ac is 60%, P123 is a mesoporous template and TEOS is a silicon source, the crystallization temperature (Y), pH (Z) and ultrasonic assisted methods for micro Kong Gui are further investigated. The effect of HAM-Y-Z formation shows that when pH is 2, a micro mesoporous silicon material with double mesoporous HAM-393-2 is prepared. When pH is 3, the HAM-393-3. alkylation of the foamed mesoporous silicon material shows that the catalyst HPW/HAM-393-3 with a larger mesoporous HAM-393-3 as the carrier load HPW has the highest catalytic activity, P. The yield of XE is 95%, which may be related to the specific surface area and pore size of the carrier, and the larger aperture is beneficial to the alkylation. To sum up, the micro mesoporous silicon materials prepared by P123 and proton type ionic liquids have higher specific surface area, larger pore diameter and unique pore structure. These advantages make the micro mesopore Silicon material can be used as catalyst carrier in alkylation reaction.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.2;TB383.4

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