节点文献
钛硅中空微球催化氧化叔胺的研究
Study on Tertiary Amine Catalytically Oxidized by Titanium-silica Hollow Spheres
【作者】 任锡玉;
【导师】 谢飞;
【作者基本信息】 中国石油大学 , 化学, 2010, 硕士
【摘要】 氧化胺是一种重要的化工中间体,分为脂型氧化胺和芳型氧化胺。氧化胺在日化、洗涤、纺织助剂、人造纤维、医药、染料、催化等诸多化工领域都有重要应用,也是常用的有机合成中间体,所以对该类化合物合成的研究具有及其重要的意义。氧化胺的制备一般通过叔胺氧化来得到,传统的催化剂一般是乙酸等均相催化剂,有后处理繁琐等诸多缺点,目前研究的多是非均相催化剂,如:杂多酸类催化剂、离子交换树脂、钛硅分子筛等。本文以钛硅中空微球作催化剂,研究了钛硅中空微球对多种叔胺的氧化作用。主要研究内容包括:具有中空结构的钛硅微球的制备,以正硅酸乙酯(TEOS)为硅源、钛酸四丁酯为钛源、以硝酸做为催化剂、Span-80为表面活性剂,煤油为油相,在新型油包水乳液体系中,采用溶胶-凝胶法制备了钛硅中空微球。分别研究了中空钛硅微球为催化剂时,以脂型叔胺吗啉为原料合成了N-甲基氧化吗啉;在芳型叔胺中分别以吡啶和2-甲基吡啶为原料合成了N-氧化吡啶和2-甲基氧化吡啶。用SEM、偏光显微镜、XRD、红外光谱、TEM等分析手段对制得的催化剂进行了微观表征。通过实验,考察了催化氧化反应中的反应温度、反应时间、物料配比等合成条件,确定了最适宜的反应工艺,并用红外光谱和核磁共振对合成产物进行了表征。研究表明,钛硅中空微球对氧化胺有良好的催化活性,N-甲基氧化吗啉的产率达到89.2%,N-氧化吡啶的产率为90.3%,2-甲基氧化吡啶产率34.4%。实验中采用过氧化氢做为氧化剂,所得到副产物为水,对环境无损害,新型钛硅中空微球作为催化剂,容易与反应物分离,制备过程工艺简便,反应过程中不需要加入任何溶剂,总体来说,钛硅中空微球是一种有效的制备氧化胺的催化剂。
【Abstract】 N-oxides of tertiary amine are a class of important organic intermediates. They are widely used in commodity, abstergent, textile auxiliary, synthetic fiber, pharmaceutical industry, coloring matter, catalysis etc. So the study of the amine oxide is of great significance.For the N-oxides of tertiary amine, the traditional catalysts used are some homogeneous catalyst such as acetic acid. Now, the heterogeneous catalysts are more widely used, such as heteropolyacid catalyst, exchange resin, Ti-Si molecular sieve etc.In this paper, the synthesis of tertiary amine oxides were studied using titanium?silica hollow spheres as catalyst. The main content is as follows: (a) Preparation of titanium?silica hollow spheres. Normaly, taking TEOS as silicon source, tetrabutyl titanate as titanium source, nitric acid as catalyst,Span-80 as surfactant, kerosene oil as oil phase in micro-emulsion system; thus the titanium?silica hollow spheres were obtianed. (b) In the presence of titanium?silica hollow spheres as catalyst, the N-methylmorpholine-N- oxidie (NMMO) was synthesized from N-methylmorpholine. (c) the pyridine N-oxide and 2-methylpyridine N-oxide were synthesized from pyridine and 2-methylpyridine. The catalysts were characterized by polarized light microscopy, scanning electron microscopy, X-ray diffraction and FT-IR. The effects of the reagent ratio, reaction temperature and reaction time on the yield of tertiary amine N-oxides were investigated in detail. The products were characterized and confirmed by FT-IR, 1HNMR. The yields of NMMO, pyridine N-oxide, 2-methylpyridine N-oxide are 89.2%, 90.3%, 34.4%, respectively.Titanium?silica hollow spheres in the presence of H2O2 have many benefits, for example, reusability, easy separation and no disposal, which is a good enviroment and useful green catalyst for oxidation of tertiary amine.
【Key words】 Titanium-silica hollow spheres; Catalytic oxidation; Hydrogen Peroxide; Tertiary amine; N-oxides of tertiary amine;