首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 78 毫秒
1.
由邻苯二甲酸酐为原料,经中间体3-羟基苯酞(3),再经溴丙烯及锡存在下3的烯丙基化、硼氢化氧化、铬酐氧化、二甲基锌甲基化,共6步反应合成了3-(3'-羟基丁基)异苯并呋喃-1(3H)-酮.  相似文献   

2.
由邻苯二甲酸酐为原料 ,经中间体 3 羟基苯酞 (3 ) ,再经溴丙烯及锡存在下 3的烯丙基化、硼氢化氧化、铬酐氧化、二甲基锌甲基化 ,共 6步反应合成了 3 (3’ 羟基丁基 )异苯并呋喃 1(3H) 酮。  相似文献   

3.
MCM-41中孔SiO2分子筛合成新方法   总被引:9,自引:0,他引:9  
以溴代十六烷基吡啶(CPBr)为模板剂,正硅酸乙酯(TEOS)为硅源,在优化的操作条件下通过S+X-I 路径合成了高结晶度的MCM-41中孔SiO2分子筛,并提高了其收率;以TG-DTA结果为基础,对分子筛脱模板剂的过程进行了优化,同时以XRD对合成物系中CPBr;TEOSHCl,H2O相对含量对MCM-41分子筛晶相结构的影响以及该结构的形成过程进行了分析,发现MCM-41结构沿S+X-I 路径的形成经过了Lamellar→Hexagonal相转移历程.  相似文献   

4.
MCM-41介孔分子筛合成研究Ⅱ.微波辐射合成法   总被引:22,自引:0,他引:22  
采用 微波辐 射技术合 成了 M C M41 介孔分 子筛,并 用 X R D , S E M , I R, N M R 和吸 附等表征手段考 察了其 晶化过程 、晶体 形 貌和 稳定 性 等特 点. 结 果表 明, 微波 法合 成 M C M41 分 子 筛时诱导期 极短,晶 化速度很 快且在晶 化后期 无转晶现 象; 微 波法 合成 的 M C M41 试样 的吸 附容 量较低,但 具有较强 的耐热及 水热稳 定性和抗 酸碱能 力  相似文献   

5.
纳米介孔分子筛MCM-41的微波辐射合成法   总被引:23,自引:0,他引:23  
报导了纳米介孔分子筛MCM-41的微波辐射合成法,运用XRD、HRTEM、IR、TG、荧光光谱和低温N2吸附等技术对其进行了表征.研究结果表明,利用微波技术合成MCM-41,操作便利,节能省时.所得产物具有六方介孔排列结构,孔径约2.5 nm;颗粒大小分布均匀,平均粒径约40 nm;比表面积和孔隙率高,吸附量大,热稳定性好;在近紫外光激发下,显示出纳米粒子的量子发光效应.  相似文献   

6.
[Ru(bpy)3]2+/MCM-41 composite material obtained by loading tris(2,2′-bipyridine)ruthenium(Ⅱ)([Ru(bpy)3]2+) in siliceous mesoporous MCM-41 was characterized by X-ray powder diffraction, UV-Vis absorption and emission spectroscopies. The absorption spectrum of [Ru(bpy)3]2+/MCM-41 is similar to that of [Ru(bpy)3]2+ aqueous solution, whereas its emission spectrum exhibits hypsochromic shift compared to the solution spectrum. On the other hand, the peak position of the emission spectrum of [Ru(bpy)3]2+/MCM-41 shifts towards longer wavelength when the loading amount increases.  相似文献   

7.
以十六烷基三甲基溴化铵为模板剂,水玻璃为硅源合成中孔分子筛MCM-41,用X射线粉晶衍射、N2吸附-脱附、透射电镜分析等手段对样品进行了表征。以MCM-41处理含铬废水,在pH值为6~6.8,Cr(VI)初始浓度为10mg/g,可使水中Cr(VI)的去除率达92.70%,饱和吸附量为86.56mg/g,符合Langmuir型吸附等温式。  相似文献   

8.
开展了2-卤代苯甲酰胺与腈类化合物反应生成喹唑啉-4(3H)-酮类衍生物的微波辅助合成研究。结果表明:在微波辅助条件下,生成的喹唑啉-4(3H)-酮类衍生物的速率均较常规加热条件下增大,并且2-碘代苯甲酰胺比2-溴苯甲酰胺活性更高。一系列的喹唑啉-4(3H)-酮衍生物被高效地合成出来,最高产率达到89%。  相似文献   

9.
向松  李一梁  辛勤  李灿 《催化学报》2002,23(5):393-394
 对于非官能团化烯烃的不对称环氧化反应,手性Mn(salen)Cl配合物是性能优异的催化剂。本文采用了一种新的方法将其固载到无机载体的表面上。从对溴苯酚出发,经三甲基氯硅烷保护酚羟基,合成了酚羟基被保护的硅烷化试剂,与无机载体进行反应,然后选择性水解,可以在无机载体的表面嫁接上酚羟基。通过Mn(salen)阳离子与酚氧阴离子的相互作用,将手性Mn(salen)配合物固载到无机载体的表面上,合成了无机载体嫁接的手性Mn(salen)催化剂。  相似文献   

10.
以十六烷基三甲基溴化铵为模板剂,硅酸钠为硅源,铝酸钠为铝源,在水热条件下成功地合成出了MCM-41中孔硅酸盐材料。采用XRD、低温N2吸附脱附等测试手段对合成的MCM-41样品进行了表征。通过优化合成条件,合成出孔径3.2 nm、比表面904m2/g和孔壁厚约1.46 nm的MCM-41分子筛。催化活性测定采用微反应活性实验来评价其活性和选择性。  相似文献   

11.
徐建华  戴维林  杨新丽  曹勇  范康年 《化学学报》2004,62(16):1467-1471
通过可溶的草酸配合物将铌酸固载到中孔分子筛MCM-41上,得到含催化氧化活性中心的Nb2O5/MCM-41负载型催化剂,并用XBD,BET,N2吸附等手段进行了表征.该催化剂在环戊烯催化氧化制备戊二醛的反应中表现出优良的催化性能,环戊烯的转化率高达100%,戊二醛收率达到50%,展现了良好的应用前景.  相似文献   

12.
Using glycerol, glycol and water as solvent, cetyltrimethylammonium bromide (CTAB) as template, tetraethyl orthosilicate (TEOS) as silica source, ethylenediamine (EDA) as base source, mesoporous molecular sieve MCM-41 has been synthesized at room temperature, characterized by X-ray power diffraction and N2 adsorption. Compared with the samples synthesized by glycol and water, the samples synthesized by glycerol have larger pore diameter and high surface areas. Thus glycerol is an efficient solvent for preparing larger pore mesoporous MCM-41.  相似文献   

13.
 利用直接合成法和后接枝法将含有磺酸基团的硅烷偶联剂引入MCM-41介孔分子筛中, 合成了酸性介孔有机-无机杂化材料. 利用XRD和TEM等方法对其结构进行了表征. 结果表明,利用直接合成法和后接枝法合成的杂化材料仍保持规整的介孔孔道,该材料作为酸催化剂在苯甲醛与乙二醇的缩醛反应中显示了较好的催化活性.  相似文献   

14.
苄基磺酸接枝MCM-41介孔分子筛的合成与表征   总被引:1,自引:0,他引:1  
陈静  韩梅  孙蕊  王锦堂 《无机化学学报》2006,22(9):1568-1572
在采用溶胶-凝胶法合成纯硅MCM-41基础上,经过两步后合成处理,在纯硅MCM-41上接枝苄基磺酸,并通过X射线衍射、低温氮气吸附、红外光谱、元素分析、热重分析和酸度滴定,对所得样品进行了表征。结果表明,经过苯甲醇、氯磺酸两步接枝处理,苄基及磺酸成功地接入MCM-41上,并保持MCM-41的介孔结构,接枝后的磺酸型MCM-41比表面积和孔容均减小,分别为 976 m2·g-1和0.42 cm3·g-1,酸量为4.2 mmol·g-1。  相似文献   

15.
以混合表面活性剂为模板可控合成MCM-48和MCM-41分子筛   总被引:2,自引:0,他引:2  
利用阳离子和三嵌段共聚物混合表面活性剂为模板,在水热条件、碱性介质中可控合成出MCM-48和MCM-41分子筛。在固定P123(聚氧乙烯-聚氧丙烯-聚氧乙烯三嵌段共聚物):TEOS(正硅酸乙酯)(物质的量的比)为0.01875的体系中,调节CTAB(十六烷基三甲基溴化铵)∶TEOS(正硅酸乙酯)物质的量比值m,当m在0.12~0.13范围合成出MCM-48分子筛;当m在0.04~0.08范围合成出MCM-41分子筛。通过XRD,TEM,N2物理吸附,IR等方法进行了表征。结果表明:聚氧乙烯-聚氧丙烯-聚氧乙烯三嵌段共聚物(P123)的加入可以更大程度地降低合成介孔材料所需阳离子表面活性剂的用量;可控合成的介孔材料具有高比表面积、高度有序的孔道结构、较集中的孔径分布。  相似文献   

16.
MCM-41 material was synthesized starting from hydrogel containing colloidal fumed silica, sodium silicate, cetyltetramethylammonium bromide(CTMABr) as surfactant, and distilled water as solvent. These reactants were mixed to obtain a gel with the following composition: 4SiO2:1Na2O:1CTMABr:200H2O. The hydrogel with pH=14 was hydrothermally treated at100°C, for 4 days. Each day, the pH was measured, and then adjusted to 9.5–10 by using 30%acetic acid solution. Thermogravimetry was the main technique, which was used to monitor the participation of the surfactant on the MCM-41 nanophase, being possible to determine the temperature ranges relative to water desorption as well as the surfactant decomposition and silanol condensation. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

17.
A series of vanadoaluminosilicate MCM-41 mesoporous molecular sieves with various compositions have been hydrothermally synthesized. Hexadecyltrimethylammonium bromide was used as a surfactant in the synthesis. The samples were characterized with nitrogen sorption, X-ray diffraction, differential thermal analysis, thermogravimetric analysis, Fourier transform-Infrared spectroscopy, UV-visible spectroscopy, scanning electron microscopy, transmission electron microscopy, and solid state NMR. The solid products had the MCM-41 structure and contained only atomically dispersed vanadium and aluminum consistent with framework vanadium and aluminum. The samples were hydrophobic and contained large amount of surfactant in the as-synthesized samples. The surfactant could be removed upon calcination at 450°C. N2 sorption measurements and TEM demonstrate the high mesoporosity of [V, Al]-MCM-41. The incorporation of vanadium and aluminum into MCM-41 decreased the surface area to some extent. The morphologies of all the samples were the agglomerate of plates. 29Si MAS NMR shows that the pore wall is amorphous. 27Al MAS NMR shows that all of aluminum species were tetrahedrally coordinated even after calcination at 550°C.  相似文献   

18.
In this work, we found that MCM-41 prepared using cetyltrimethyl ammonium bromide (CTAB) as the template could be used as a heterogeneous catalyst for the reaction of methanol with propylene oxide to produce propylene glycol methyl ether. 1-Methoxy-2-propanol was the predominant product. The influence of ratio of the reactants, reaction temperature, and time on the yield and selectivity was studied. The as-prepared MCM-41 proved to be an efficient and reusable catalyst, and the separation of the catalyst form the product was very easy.

Additional information

ACKNOWLEDGMENTS

The authors are grateful to the Ministry of Science and Technology of China (2006CB202504, 2009CB930802) and the National Natural Science Foundation of China (20932002).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号