ZSM-5/MCM-41复合分子筛的合成与表征

以碱处理的ZSM-5浆液为硅铝源,通过水热自组装过程合成了介孔-微孔复合孔道结构的分子筛,并采用XRD、BET、HRTEM、Py-IR和水热处理等手段对合成分子筛进行了表征。结果表明,碱处理ZSM-5时的苛刻程度是影响复合分子筛合成的重要因素,适宜的碱处理条件为NaOH浓度1 mol/L、80℃时处理1 h。表征结果表明,复合分子筛具有规整互通的微孔-介孔梯级复合孔道结构,孔容、比表面积和平均孔径分别为0.63 mL/g,684 m²/g和3.76 nm,属典型的MCM-41结构;与MCM-41相比,复合分子筛的B酸(尤其是强B酸)酸量明显增强,水热稳定性显著提高。     

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。     

以十六烷基三甲基溴化铵为模板剂合成MCM-41/ZSM-5复合分子筛的研究

采用阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)为模板剂、以ZSM-5为晶种,在水热晶化条件下合成了同时具有微孔和介孔的MCM-41/ZSM-5复合分子筛;并考察了陈化温度、陈化时间、晶化时间及模板剂用量等条件对合成复合分子筛的影响.通过X射线衍射、扫描电镜、高分辨率透射电镜、红外光谱及N2静态吸附法等手段对合成样...     

Kinetic study of template removal of MCM-41 nanostructured material

The siliceous MCM-41 molecular sieve was synthesized starting from a hydrogel with the following molar composition: 4.58SiO₂:0.437Na₂O:1CTMABr:200H₂O. The cetyltetramethylammonium bromide (CTMABr) was used as structure template. A kinetic study of template removal after the syntheses was performed by Vyazovkin model-free kinetic method obtaining apparent activation energy of 166±8.2 kJ mol^-1. This revised version was published online in August 2006 with corrections to the Cover Date.     

MCM-41/MOR复合分子筛的制备及其烷烃异构化性能研究

以碱处理的MOR浆液为部分硅铝源、十六烷基三甲基溴化铵（CTAB）为模板剂,采用水热法合成了微孔-介孔复合分子筛MCM-41/MOR,并通过XRD、HRTEM、BET、Py-FTIR以及水热处理等方法对合成的复合分子筛进行了表征。结果表明,合成的复合分子筛具有微孔和介孔双重孔结构,比表面积高达567 m²/g,孔容为0.60 mL/g,平均孔径为3.26 nm,且具有较高的水热稳定性。正己烷在微反装置上的非临氢异构化反应结果表明,适宜的B酸和L酸协同构成了烷烃异构化的活性中心,催化剂表面的Ni离子在活化烷烃的同时还具有较好的酸性调变作用;与Ni-MOR、Ni-MCM-41以及HMCM-41/MOR相比,复合分子筛Ni-MCM-41/MOR由于其适宜的表面酸性和孔道结构,具有更好的异构化催化性能,正已烷转化率为34.40%,i-C₆⁰选择性提高到40.38%。     

Study of the Adsorption Properties of MCM-41 Molecular Sieves Prepared at Different Synthesis Times

The variation of surface properties of SiMCM-41 and AlMCM-41 nanoporous materials as function of synthesis time was examined. The main properties studied were: surface area, pore diameter, pore volume, mesoporous parameter, and wall thickness. Siliceous MCM-41 molecular sieves were synthesized starting from hydrogels with the following molar compositions: 4.58SiO₂:0.435Na₂O:1 CTMABr:200 H₂O for SiMCM-41, and 4.58SiO₂:0.485 Na₂O:1 CTMABr:0.038 Al₂O₃:200 H₂O, for AlMCM-41. Cetyltrimethylammonium bromide (CTMABr) was used as the structural template. The crystallographic parameters were obtained from XRD data and by nitrogen adsorption using the BET and BJH methods. The results obtained showed a significant variation of the surface properties of the MCM-41 materials as a function of the synthesis time reaching silica wall thickness of ca. 2 nm on the fourth day.     

非水介质中合成介孔分子筛MCM-41

首次采用十六烷基三甲基溴化铵为模板剂、正硅酸乙酯为硅源, 分别使用无机和有机弱碱, 溶剂热晶化法在非水甘油介质中合成了介孔分子筛MCM-41, 通过XRD, N₂吸附-脱附, TG-DTG, IR, SEM等测试手段对样品进行了表征分析, 结果表明在甘油体系中得到的样品具有优良的孔结构性质. 相比于氢氧化钠, 以有机弱碱(无水乙二胺、三乙胺)作为碱源, 可以得到有序性更好、结晶度高的样品, 样品具有较窄的孔径分布.     

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.     

中孔分子筛MCM-41的合成与表征

以白炭黑和正硅酸乙酯为硅源,十二、十六烷基三甲基铵为模板剂,用水热法和室温直接法合成出中孔分子筛MCM-41,考察了对合成的影响因素,用红外光谱、吸附、孔分布、热分析等手段对这两种产物进行了表征。结果表明:这种分子筛可以在很宽的配比范围内获得,但较高水硅比更有利于合成;在水硅比较低的体系中得到了一种类MCM-41中孔相(亦应属于MCM-41),其XRD衍射峰较宽,2θ角度偏低,具有类似于无定形硅铝酸盐的骨架结构。     

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.     

中孔沸石新材料MCM－41──Ⅰ．合成、酸性及稳定性

中孔沸石新材料ＭＣＭ－４１──Ⅰ．合成、酸性及稳定性赵修松，王清遐，徐龙伢，谢紊娟（中国科学院大连化学物理研究所，大连１１６０２３）李新生（中国科学院大连化学物理研究所催化基础国家重点实验室，大连１１６０２３）关键词ＭＣＭ－４１沸石，合成，酸性，稳定...     

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.     

预置晶种合成MCM-41/ZSM-3复合分子筛

以十六烷基三甲基溴化铵和四甲基氢氧化铵为模板剂，以ZSM-3为晶种，在水热条件下合成了同时具有中孔和微孔的复合分子筛MCM-41/ZSM-3。通过XRD、IR、N2吸附脱附等温线和SEM表征，样品的XRD图谱在小角度衍射区和大角度衍射区同时出现了MCM-41和ZSM-3的衍射峰；IR图谱上也同时出现了MCM-41和ZSM-3的吸收谱带，并且合成样品与两种分子筛的机械混合物有明显差别；N2吸附脱附等温线证明样品含中孔和微孔结构，并且微孔直径集中分布在0.7 nm左右，中孔直径集中分布在3.3 nm左右；从SEM照片可以看出，复合分子筛和机械混合物形貌不同，前者为附晶生长或再结晶，后者为均匀分散。     

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.     

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     

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.     

MCM－41中孔分子筛的合成及其性质

以十六烷基三甲基溴化铵（ＣＴＡＢ）作模板剂，研究了水热体系中中孔ＭＣＭ－４１分子筛的合成条件。在Ｈ_２Ｏ／Ｓｉ介于１２～１００，Ｓｉ／Ａｌ介于１０～∞，ＣＴＡＢ／Ｓｉ介于０．０８～０．２时，可以合成出ＭＣＭ－４１分子筛。在加入煤油等混合烃的合成体系中，可以合成出孔径大于４ｎｍ的ＭＣＭ－４１分子筛。用ＸＲＤ、ＳＥＭ、Ｎ_２吸附对合成样品加以表征，证明它们具有典型的中孔分子筛特性。探针反应证明它具有中强酸中心。     

A Novel Method for the Synthesis of Mesoporous Molecular Sieve MCM-41

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.     

氨水介质中含Ti的MCM-41介孔分子筛的合成

 在氨水介质中采用TiCl3和正硅酸乙酯合成了含Ti量不同的MCM-41介孔分子筛. 该方法可避免使用昂贵的辅助模板剂,也不需要加入醇来调节水解速度,因而合成过程相对简单、易于控制. 采用XRD和N2吸附-脱附等技术对介孔分子筛的结构进行了表征. 结果表明,合成的MCM-41介孔分子筛的六方介孔有序性好,结晶度高. UV-Vis光谱表明,Ti-MCM-41在200～300 nm间出现了四个清晰可辨的吸收峰,说明Ti原子以多种状态存在于介孔分子筛骨架中.     

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。