摘要SBA-15介孔分子筛具有比表面积大,孔径分布均一且在较宽范围内可调的优 势,但其活性位点较少,本文通过过渡金属掺杂改性SBA-15的制备,并在此基础上 进行微介孔的合成来增加其酸性活性位点。采用单一模板剂三嵌段共聚物P123, 以正硅酸乙酯为硅源,用水热法制备出纯SBA-15,考察了矿化剂KCl不同含量对 SBA-15的影响,通过XRD表征发现当KCl的含量为4.48g时其小角衍射峰强度更高。 在此基础上,用水热法分别合成出Al/Si=0.01、0.02的Al/SBA-15和Fe/Si=0.01 的Al-Fe-SBA-15, XRD和SEM分析结果表明合成的分子筛为二维六方相介孔结构。 并探索了微介孔结构的合成,以Al-SBA-15为前驱体,加入到对应量的TPAOH和乙 醇溶液中,在碱性条件下部分溶解SBA-15,以期合成SBA-15/ZSM-5,实验表明TPAOH 的量对获得SBA-15/ZSM-5并无影响,而不同的温度及晶化时间会影响产物的生成, 重结晶的最佳温度在150-180℃之间,最佳的晶化时间以24h为宜。68553
毕业论文关键词:SBA-15 Al-Fe-SBA-15 微介孔分子筛
Title Study on Preparation of SBA Modified with Transition Metal
Abstract
Mesoporous SBA-15 has advantages of large specific surface area, sharp pore size distribution which is adjustable over a wide range, but it has very few active sites. In order to increase its acid active sites, SBA-15 was prepared with transition metal doping, and micro-mesoporous zeolites was also synthesized with attemption. The pure SBA-15 was prepared by hydrothermal method which used a single template tri-block copolymer P123 and TEOS as silica source. The effects of different amounts of mineralizing agent KCl on SBA-15 morphology were investigated. It is showed in XRD that the content of 4.48g KCl is the best for forming ordered mesoporous structure. Based on this amount, the Al-SBA-15(Al/Si= 0.01,0.02) and Al-Fe-SBA-15 (Fe/Si =0.01) was synthesized by hydrothermal method. Characterized by XRD and SEM, the analysis shows that the synthetic zeolites is a two-dimensional hexagonal mesoporous structure. The micro-mesporous zeolites was also researched in this paper, the Al-SBA-15 was added to the mixture of corresponding amount of TPAOH solution and ethanol in order to get partial dissolution of SBA-15 under basic conditions and synthesized SBA-15/ZSM-5. It shows that the amount of TPAOH has no effects on the synthesis of SBA-15/ZSM-5, and different temperature and crystallization time would affect the product. The optimum temperature of recrystallization is between 150-180 ℃, and optimum crystallization time is 24h.
Key words: SBA-15 Al-Fe-SBA-15 micro-mesporous zeolites
目 次
1 引言 1
1.1 研究背景及意义 1
1.2 介孔分子筛的分类 2
1.3 SBA 介孔分子筛的合成 2
1.4 SBA 介孔分子筛研究进展 3
1.5 本文主要研究内容 5
2 SBA-15 及 Al、Fe 掺杂 SBA 的制备 6
2.1 实验试剂及仪器 6
2.2 SBA-15 合成方法 6
2.3 Al-SBA-15 及 Al-Fe-SBA-15 的制备 7
2.4 SBA-15 表征手段 7
2.5 结果与讨论 8
3 SBA-15/ZSM-5 的制备 13
3.1 实验试剂及仪器 13
3.2 SBA-15/ZSM-5 的制备 13
3.3 表征手段 过渡金属掺杂SBA的制备工艺研究:http://www.751com.cn/huaxue/lunwen_77134.html