Pt-Al/MCM-41催化剂的制备及催化合成有机硅增效剂

以介孔硅MCM-41为载体,AlCl₃为促进剂,制备了负载型Pt-Al/MCM-41催化剂。利用傅里叶红外光谱（FTIR）、N₂吸附-脱附、X射线衍射（XRD）、透射电子显微镜（TEM）、X射线光电子能谱（XPS）、电感耦合等离子体发射光谱（ICP）对催化剂的结构、形貌以及金属间作用力进行了表征,着重探讨了不同Al加入量对催化剂结构和金属间作用力的影响,系统考察了Pt-Al/MCM-41用于催化聚乙二醇烯丙基醚和七甲基三硅氧烷合成有机硅增效剂。结果表明,Al的加入量对催化剂的结构和有序度有一定的影响,其比表面积、孔容和有序度随着Al用量的增加而逐步降低。此外,加入一定量的Al有利于提高Pt晶粒的分散度,减小其粒径。Pt₁Al₂/MCM-41催化剂具有良好的重复使用性,使用6次无明显失活,其转化率仍大于90%。合成有机硅增效剂的最佳工艺为：n_PGAE/n_MD^HM=1.1,反应时间为4 h,反应温度为100℃,催化剂用量为0.5%,其转化率达94.1%。     

Pt-Al/MCM-41催化剂的制备及催化合成有机硅增效剂

以介孔硅MCM-41为载体,Al Cl_3为促进剂,制备了负载型Pt-Al/MCM-41催化剂。利用傅里叶红外光谱(FTIR)、N_2吸附-脱附、X射线衍射(XRD)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)、电感耦合等离子体发射光谱(ICP)对催化剂的结构、形貌以及金属间作用力进行了表征,着重探讨了不同Al加入量对催化剂结构和金属间作用力的影响,系统考察了Pt-Al/MCM-41用于催化聚乙二醇烯丙基醚和七甲基三硅氧烷合成有机硅增效剂。结果表明,Al的加入量对催化剂的结构和有序度有一定的影响,其比表面积、孔容和有序度随着Al用量的增加而逐步降低。此外,加入一定量的Al有利于提高Pt晶粒的分散度,减小其粒径。Pt_1Al_2/MCM-41催化剂具有良好的重复使用性,使用6次无明显失活,其转化率仍大于90%。合成有机硅增效剂的最佳工艺为:n_(PGAE)/n_(MDHM)=1.1,反应时间为4 h,反应温度为100℃,催化剂用量为0.5%,其转化率达94.1%。     

杂化MCM-41固载催化剂的合成、表征及催化研究

用γ-氯丙基三乙氧基硅烷和正硅酸乙酯混合在模板剂引导下共水解合成了有机-无机杂化的介孔分子筛MCM-41,通过与(1R,2R)-1,2-环己二胺和[RuCl2(p-cymene)]2反应,制成了固载化的不对称氢转移反应催化剂,并进行了FT-IR、XRD和N2吸附 脱附的表征.不对称氢转移催化反应结果表明,在催化还原苯乙酮成α-苯乙醇的反应中,平均转化率为6.42％,产物平均ee（对映体过量）值为12.64％,固载化催化剂与其匀相体系的催化性能相比(转化率为3.56％,ee值为33.04％),转化率更高,ee值有一定程度的降低.     

多相对映体选择性环氧化催化剂Mn(salen)/MCM-41的合成

 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。     

嫁接Al改性MCM-41介孔分子筛催化合成双酚F

以十六烷基三甲基溴化铵和正硅酸乙酯为原料,合成纯硅MCM-41介孔分子筛。 再利用九水硝酸铝为改性剂来嫁接改性纯硅MCM-41介孔分子筛,NH3-TPD结果表明,嫁接后的AlMCM-41产生了中强酸。 用改性后不同n(Si)/n(Al)的AlMCM-41催化合成双酚F,在n（苯酚）/n（甲醛）=30、反应时间5 h、反应温度90 ℃、m（甲醛）/m（AlMCM-41）=7的反应条件下,在一定范围内,双酚F的产率随Al含量增加而增加,但在n（Si）/n（Al）＜50时,双酚F的产率反而下降,当n（Si）/n（Al）=50时,双酚F的产率最高,为42.28%。     

Synthesis of Propylene Glycol Methyl Ether Catalyzed by MCM-41

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.

以混合表面活性剂为模板可控合成MCM-48和MCM-41分子筛

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。     

AlCl3/MCM-41催化剂上桥式四氢双环戊二烯异构化反应

 分别采用介孔 MCM-41 和 SiO2 为载体制备了固载化 AlCl3 催化剂, 考察了其催化桥式四氢双环戊二烯异构化生成挂式四氢双环戊二烯反应性能. 结果表明, 180 °C 时 AlCl3/MCM-41 催化剂上挂式四氢双环戊二烯选择性可达 95.7%, 而在 AlCl3/SiO2 上仅为 86.3%. 采用 N2 吸附-脱附、Hammett 指示剂法、吡啶吸附红外光谱和化学分析等方法对催化剂进行了表征. 结果表明, AlCl3/MCM-41 催化剂较弱的表面酸性和一维孔结构有利于挂式四氢双环戊二烯的生成.     

磺酸基功能化MCM-41有机-无机杂化材料的合成与表征

 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.     

MCM-41固载胺钯配合物的制备及对Heck反应催化性能的研究

以MCM-41分子筛作为固载材料, 经氨基功能化后与各种钯化合物形成一系列MCM-41载钯配合物, 采用XRD, XPS等技术对其结构及表面性能进行了表征, 研究了催化剂的制备条件等因素对催化Heck芳基化反应性能的影响; 以共轭烯烃和各种芳基碘的Heck芳基化反应考察了MCM～NH₂•Pd(0, II)配合物的催化性能. 结果表明, MCM-41的结构没有被破坏, MCM～NH₂载钯配合物具有较高的催化活性和立体选择性, 在较低的温度(70～90 ℃)下, 可高产率地生成一系列取代的反式产物.     

The Synthesis and Characteristics of Vanadoaluminosilicate MCM-41 Mesoporous Molecular Sieves

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.     

Synthesis of MCM-41 supported amino-palladium complex and its catalytic performance for heck reaction

Using MCM-41 as the supporter, a series of MCM-41 supported amino-palladium complexes has been prepared and characterized by XRD (X-ray diffraction) and XPS (X-ray photoelectron spectroscopy), etc. The XRD and XPS results indicate that the Pd coordinates with the -NH₂ groups on the MCM-41 surface, and the structure of MCM-41 has been not damaged. Its catalytic performance for Heck arylation of alkene with aryl iodide shows that the catalysts have high activity and stereoselectivity in 70–90°C. The product of Heck reaction is in E form. And the effect of the preparation condition of catalyst on the catalytic performance was examined. Translated form Chinese Journal of Organic Chemistry, 2008, 28(5) (in Chinese)     

水解对MCM-41分子筛的结构破坏作用

详细考察了ＳｉＭＣＭ－４１、ＡｌＭＣＭ－４１和ＨＡｌＭＣＭ－４１在不同环境中的水解和结构破坏情况．空气和水蒸汽中短期高温焙烧对全硅型ＳｉＭＣＭ－４１的结构影响较小,但在潮湿空气中长期放置可因Ｓｉ—Ｏ—Ｓｉ键发生水解而造成结构的严重破坏．ＡｌＭＣＭ－４１的抗水解能力优于ＳｉＭＣＭ－４１的,但因其结构中包含一定量的Ｎａ＋离子,降低了高温焙烧时结构的热稳定性和水热稳定性．ＨＡｌＭＣＭ－４１的热稳定性和水热稳定性均优于ＡｌＭＣＭ－４１．分子筛水热晶化过程中的盐析效应被证实是导致ＡｌＭＣＭ－４１和ＨＡｌＭＣＭ－４１抗水解能力增强的原因,因此在合成原料中加盐可显著改善ＭＣＭ－４１分子筛的抗水解能力和稳定性     

功能化MCM-41固载的钌基催化剂上二氧化碳加氢合成甲酸

采用两种方法制备了功能化MCM-41固载的钌基催化剂,并用原子吸收光谱,紫外可见光谱以及红外光谱等手段对其进行表征。结果表明,钌基在功能化MCM-41上顺利固载。将这两种固载的钌基催化剂用于二氧化碳加氢合成甲酸反应,发现在较低反应温度和较低氢分压下,固载的RuCl2(PPh3)3催化剂表现出更高的催化活性,在反应温度80℃,H2分压5MPa, CO2分压8MPa下,甲酸转化数达到1275。固载的RuCl2(PPh3)3催化剂也表现出很好的重复再用性。     

锌锡双金属掺杂MCM-41的合成及表征

以硅酸钠为硅源, 锡酸钠，硝酸锌为金属源，十六烷基三甲基溴化铵为模板剂，采用直接水热合成法合成出了锌锡双金属同时掺杂的介孔MCM-41。通过ICP﹑XRD、TG-DTA﹑FTIR﹑HRTEM以及BET等技术对材料的结构和性质进行了表征。结果表明，合成的材料具有典型的六方介孔结构，比表面高，孔分布窄，热稳定性较高，且锌锡可能进入介孔MCM-41骨架中。该材料对苯酚羟基化反应具有良好的催化性能，双金属修饰MCM-41催化活性明显优于单组分掺杂。     

Thermogravimetric Investigations During the Synthesis of Silica-based MCM-41

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.     

MCM-41负载硫醚钯配合物的合成及其催化芳基卤化物的羰基化性能

γ-(β-氰乙硫基)丙基三乙氧基硅烷依次用纳米介孔分子筛(MCM-41)固载、与氯化钯反应, 合成了MCM-41负载硫醚钯配合物. 该新型负载钯配合物是芳基卤化物的羰基化反应的有效催化剂, 为各种取代的N-苯基苯甲酰胺、苯甲酸丁酯的合成提供了方便实用的新途径.     

WP／MCM-41催化剂的制备及其加氢脱硫性能

以磷钨酸铵、磷酸氢二铵和自制的MCM-41为原料,采用超声波振荡、程序升温和高纯氢气还原的方法制备了高比表面积的WP和WP/MCM-41,用XRD、BET、BJH、SEM和EDX表征了所制备的催化剂,并考察了催化剂对噻吩的加氢脱硫性能.结果表明,采用超声波振荡法制得的WP催化剂其比表面积、孔容和对噻吩加氢脱硫活性明显高于常规搅拌制得的WP催化剂,WP的比表面积达到56.357 m2/g,孔容达到0.058 cm3/g,35%WP/MCM-41催化剂的比表面积分别为287.522 m2/g,孔容为0.362 cm3/g,在613 K时WP催化剂的噻吩转化率达到81.22%,负载量为35%的WP/MCM-41催化剂的噻吩转化率达到92.78%;35%WP/MCM-41的噻吩HDS活性较好.     

Synthesis of Thermally Stable MCM-41 at Ambient Temperature

A new process to synthesize thermally stable mesoporous molecular sieves of MCM-41 structure based on delayed neutralization at ambient temperature was investigated. All samples synthesized by this new method have BET surface areas of about 1100m²/g and possess high thermal stability up to 900°C. Higher crystallinity and less lattice constriction after calcination were observed for samples with a longer aging period. Those samples with aging time longer than 10 days exhibited four characteristic XRD peaks of MCM-41 both before and after calcination at 560°C. The N₂ adsorption-desorption isotherms of the calcined samples showed larger average pore size and more homogenous pore size distribution. The method was also successfully applied to the synthesis of MCM-41 with different surfactants of hydrocarbon length with 10–18 carbons and proves to be a simple route for obtaining thermally stable MCM-41 at room temperature.