双介孔钛硅球的可控合成及绿色催化氧化研究硕士学位论文

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1、 硕士学位论文硕士学位论文 双介孔钛硅球的可控合成及绿色催化氧化 研究 THE THE CONTRALLABLE CONTRALLABLE SYNTHESIS OF SYNTHESIS OF TITANOSILICATE BEADS WITH BIMODAL TITANOSILICATE BEADS WITH BIMODAL MESOPORE AND ITS APPLICATION AS GREEN MESOPORE AND ITS APPLICATION AS GREEN EPOXIDATION CATALYSTSEPOXIDATION CATALYSTS 张世超张世超 哈尔滨工业大学哈尔滨

2、工业大学 2012014 4 年年 7 7 月月 国内图书分类号：O614 学校代码：10213 国际图书分类号：540 密级：公开 理学硕士学位论文理学硕士学位论文 双介孔钛硅球的可控合成及绿色催化氧化 研究 硕 士 研 究 生 ： 张世超 导 师 ： 林凯峰副教授 申请学位 ： 理学硕士 学科 ： 无机化学 所 在 单 位 ： 理学院 答 辩 日 期 ： 2014 年 7 月 授予学位单位 ： 哈尔滨工业大学 Classified Index: O614 U.D.C: 540 Dissertation for the Master Degree in Science THE THE CON

3、TRALLABLE CONTRALLABLE SYNTHESIS OF SYNTHESIS OF TITANOSILICATE BEADS WITH BIMODAL TITANOSILICATE BEADS WITH BIMODAL MESOPORE AND ITS APPLICATION AS GREEN MESOPORE AND ITS APPLICATION AS GREEN EPOXIDATION CATALYSTSEPOXIDATION CATALYSTS CandidateCandidate： Zhang Shichao SupervisorSupervisor： Associat

4、e Prof. Lin Kaifeng Academic Degree Applied forAcademic Degree Applied for： Master of Science SpecialitySpeciality： Inorganic Chemistry AffiliationAffiliation： School of Science Date of DefenceDate of Defence： July, 2014 DegreeDegree- -ConferringConferring- -InstitutionInstitution： Harbin Institute

5、of Technology 哈尔滨工业大学理学硕士学位论文 - I - 摘 要 有序介孔分子筛自从 M41S 系列氧化硅材料被报道而逐渐成为一个热门的研究领域，具有高比表面积的介孔材料在多相催化、吸附分离、光学和传感器等领域具有广泛的应用前景。在催化过程中，人们希望有序的介孔结构能提高材料活性中心的利用率，然而在某些大分子参与的反应中，M41S 系列分子筛表现的却不如人意，这是由于规则有序的介孔孔道内发生了堵塞而使催化剂的性能降低。 本文在室温条件下以氨水或四丙基氢氧化铵作碱源的体系中，通过一锅双模板法得到了具有一定宏观尺寸的双介孔钛硅球。 然后采用了 XRD， FT-IR， UV-vis，氮

6、气吸附脱附， SEM 和 TEM 等测试方法对样品进行了表征， 结果表明该钛硅球的内部结构是由 3.5 nm 的较小介孔和 30 nm 左右的较大介孔组成。在合成过程中，深入研究了树脂含量、水热合成温度、钛源种类和钛源加入量等因素对样品的影响。为探究引入二级孔道(较大介孔)对其样品性能产生的影响，将双介孔钛硅球作为催化剂分别应用于双氧水参与的环己烯、 顺-环辛烯、 环十二烯和反， 反， 顺-1, 5, 9-环十二烷基三烯的环氧化反应中。 实验结果表明，对于环己烯的环氧化反应，双介孔钛硅球在环己烯的转化率和环氧化合物的选择性分别为 33.7%和 21.3%，远高于传统的介孔分子筛Ti-MCM-4

7、1；而对于分子更大的环烯烃环氧化反应，双介孔钛硅球表现出了更高的催化活性。在环己烯的环氧环反应中，探究了催化剂的重复利用性的问题，结果发现，双介孔钛硅球可以实现三次以上重复利用而不会造成明显的钛物种流失，并且在反应结束后基本保持微球结构，这也保证了催化剂从反应体系中自动的分离。 关键字：双介孔；钛硅微球；大环烯烃；环氧化 哈尔滨工业大学理学硕士学位论文 - II - Abstract Since the first report of mesoporous MCM-41 material, there has been intense activity in the design and sy

8、nthesis of a variety of porous solids with high surface areas and uniform and unimodal framework mesopores due to their potential applications as advanced catalysts, adsorbents, optical guides and sensors. As extensively discussed elsewhere, the accessibility to the active sites could be effectively

9、 improved via the uniform mesopore systems in many catalytic applications of bulky molecules. Without prejudice to the above, however, it has been noted that the principal feature of MCM-41 and the related solids could not always offer expected advantages in certain catalytic applications. Even more

10、, precisely owing to a typical uniform pore system, unimodal porous materials might suffer from poor accessibility to active sites because of pore blocking. In our work, bimodal mesoporous titanosilicate beads (BMB-TiSil) were prepared by using aqueous ammonia or tetrapropylammonium hydroxide (TPAOH

11、) as alkali source via a one-pot dual-templating method, where cetyltrimethylammonium bromide (CTAB) acted as a template for framework mesopores and anion-exchange resin (Amberlite IRA-900) beads as a shape- and large-mesopore-directing agent. BMB-TiSil were characterized by XRD, FT-IR, UV-vis, N2 a

12、dsorption-desorption, SEM and TEM measurement. The method presented here provides an approach to synthesize bimodal mesoporous titanosilicate beads with framework mesopores at size of 3.5 nm and continuous large mesopores at size of 30.7 nm. In addition, we also investigate some synthetic conditions

13、 deeply, such as resin content, the hydrothermal temperature and the type and contention of titanium source. The bimodal pore character results in high accessibility to the active tetrahedral Ti species and, in turn, enhances catalytic activity. In practice, BMB-TiSil showed higher turnover frequenc

14、y. The cyclohexene conversion and epoxide selectivity in the green epoxidation of cyclohexene with aqueous H2O2 was 33.7 and 21.3 %, respectively. In the cases of epoxidation of alkenes bulkier than cyclohexene, such as cyclooctene, cyclododecene and trans, trans, cis-1, 5, 9-cyclododecatriene, the

15、advantage of BMB-TiSil on catalytic activities is more pronounced, confirming the role of the continuous large mesopore system on the improved accessibility. Importantly, BMB-TiSil is a stable catalyst immune to titanium leaching, and can be reused in three successive catalytic cycles without significant loss of activity. KeywordKeywords s: : Bimodal mesoporous，Titanosilicate beads, Epoxidations, Green catalyst，bulk alkenes 哈尔滨工业大学理学硕士学位论文 - III - 目 录 摘 要 . I Abstract.