Synthesis,Characterization and Catalytic Applications of Organized Mesoporous Aluminas

The synthesis of organized mesoporous aluminas has opened a very interesting area for application of this type of materials, particularly as catalysts or catalyst supports. This review focuses on the individual synthesis routes to produce organized mesoporous aluminas with large surface areas and narrow pore size distributions, and on the evaluation of their textural, chemical and thermal properties and outlines examples of catalytic applications of organized mesoporous alumina‐based catalysts. We tried to rationalize the synthetic approaches to prepare organized mesoporous aluminas, to relate their properties to synthetic procedures used as well as to their catalytic behavior in different reactions. Utilization of various structure‐directing agents for “cationic,” “neutral,” “anionic,” “nanocasting,” and special approaches leading to scaffolding and lathlike organized mesoporous aluminas is discussed in the first part of this review, as well as textural and structural characterization and thermal stability of mesoporous aluminas synthesized by different synthetic approaches. In the second part, catalytic applications of organized mesoporous aluminas described in the open literature are evaluated from the standpoint of the importance of these reactions for technological applications.     

Perspectives of Micro/Mesoporous Composites in Catalysis

This article covers the recent development in the remarkably growing field of synthesis, characterization and particularly catalytic investigation of zeolite‐based materials combining micro‐ and mesoporous features. New synthetic approaches for preparation of micro/mesoporous composites including recrystallization of originally amorphous matter, utilization of nanocrystalline zeolite seeds and formation of mesoporous zeolite single crystals are the first focus of this article. The advantages and disadvantages of composite materials in comparison with pure micro‐ and mesoporous molecular sieves will be discussed, as well. The relevance of individual experimental techniques for analysis of the composites, i.e., their structure, porosity, chemical composition, morphological features, and so on, are described in the second section of the article. The last Section is focused on the application of micro/mesoporous composites and mesoporous zeolites as catalysts in acid‐catalyzed reactions, oxidation reactions and synthesis of fine chemicals. The potential of the composites in challenging areas of catalysis for future applications is the final objective of the review.     

Perspectives of Micro/Mesoporous Composites in Catalysis

This article covers the recent development in the remarkably growing field of synthesis, characterization and particularly catalytic investigation of zeolite-based materials combining micro- and mesoporous features. New synthetic approaches for preparation of micro/mesoporous composites including recrystallization of originally amorphous matter, utilization of nanocrystalline zeolite seeds and formation of mesoporous zeolite single crystals are the first focus of this article. The advantages and disadvantages of composite materials in comparison with pure micro- and mesoporous molecular sieves will be discussed, as well. The relevance of individual experimental techniques for analysis of the composites, i.e., their structure, porosity, chemical composition, morphological features, and so on, are described in the second section of the article. The last Section is focused on the application of micro/mesoporous composites and mesoporous zeolites as catalysts in acid-catalyzed reactions, oxidation reactions and synthesis of fine chemicals. The potential of the composites in challenging areas of catalysis for future applications is the final objective of the review.     

四乙烯五胺功能化有序介孔氧化铝的合成及其CO2选择吸附性能研究

以九水硝酸铝为铝源,非表面活性剂柠檬酸为模板剂,稀氨水为沉淀剂合成有序介孔氧化铝（ OMA）。以四乙烯五胺（ TEPA）为活性组分,采用物理浸渍将其负载到OMA的内孔及比表面上,制备出氨基功能化的OMA用于CO2的选择吸附研究。采用XRD、BET和TEM对合成的吸附剂进行表征,通过自制的固定床反应器测量穿透曲线的方法研究其对CH4／CO2混合气的吸附分离性能。分别考察了负载量和吸附温度对吸附性能和分离因子的影响。结果表明,TEPA负载量为50％的吸附剂、吸附温度为70℃时对CO2吸附量最大,为2．598 mmol／g,TEPA／OMA经过10次吸附-脱附循环后,其吸附性能变化较小,仅下降了8．65％,具有较好的循环稳定性。     

硅铝介孔分子筛的合成和表征及其催化异构化性能的研究

以正硅酸乙酯(TEOS)为硅源,十六烷基三甲基溴化铵(CTABr)为模板剂,三氯化铝为铝源在室温条件下合成了介孔硅铝分子筛A1-MCM-41。采用红外光谱(IR)、X射线衍射(XRD)、低温氮吸附等温线等方法对分子筛进行了结构表征。评价结果表明,A1-MCM-41分子筛对桥式四氢双环戊二烯(endo-TCD)具有良好的催化异构化性能。     

Synthesis, Characterization and Catalytic Properties of Mesoporous Cobalt Aluminophosphate Molecular Sieves

Isomorphously substituted cobalt(II) hexagonal mesoporous aluminophosphate (CoHMA) molecular sieves were synthesized hydrothermally and characterized by various analytical and spectroscopic techniques. It was deduced that cobalt ions exhibit a divalent oxidation state in tetrahedral coordination in mesoporous aluminophosphates. Further, unlike cobalt-containing microporous aluminophosphate molecular sieves, Co(II) ions remain in a tetrahedral geometry even after calcination. The catalytic activity of CoHMA was tested for the cyclohexane oxidation reaction under mild conditions. Remarkable substrate conversion and product (cyclohexanol) selectivity were obtained compared to several previously reported heterogeneous catalysts.     

介孔氧化铝的合成及应用

通过对介孔氧化硅合成工艺的优化与修正可以用来制备介孔氧化铝分子筛。在合成介孔分子筛的前驱物中掺杂其他金属元素而将其引入骨架或将活性组分负载到介孔分子筛的基体上,可以实现对介孔分子筛表面进行表面修饰与改性,以调变分子筛表面的酸催化性能。本文综述了介孔氧化铝合成、改性研究的历史与现状,及在酸催化过程中的应用。     

Synthesis and Catalytic Applications of Mesoporous Polymer Colloids in Olefin Hydrosilylation

Mesoporous polymer particles (MPPs) have been synthesized by using the spherical microparticles of siliceous mesocellular foam (MCF) as a hard template. The MPPs possessed a robust structure with ultralarge mesopores, and a clean and inert surface. The surface properties of the MPPs could be tailored for various applications by using different functionalized monomers. An imidazolium‐pyrrolidine ligand was successfully immobilized onto MPPs and used as a supported platinum organometallic catalyst in olefin hydrosilylation. The MPP‐supported catalyst provided superior activity and selectivity for this reaction as compared to the MCF‐supported catalyst.     

Catalytic Aluminas: Surface Models and Characterization of Surface Sites

Abstract

In recent years polyurethanes have been confronted with several challenges. Some of these challenges have been overcome with the development of new catalysts. This review article covers recent developments in the field of polyurethane catalysis. An overview of the different types of catalysts, their applications, and their actuation mechanisms, followed by a general survey of the stability of one‐component polyurethane systems in which the latent catalyst is already incorporated is presented.     

含钛介孔SiO2 催化剂的合成及其催化性能

分别以廉价硅酸钠与正硅酸乙酯为硅源,通过复合模板剂制备了介孔二氧化硅,并利用吸附相反应技术合成了TiO2/SiO2复合催化剂。用X射线衍射(XRD)、红外谱图分析(FT-IR)等手段对其结构进行了表征,通过苯酚的羟基化反应考察了催化剂的催化性能。     

Synthesis, Characterization and Catalytic Activities of Mesoporous AlMSU-X with Wormhole-Like Framework Structure

Mesoporous AlMSU-X molecular sieves with high acidity have been prepared from preformed beta nanoclusters under strong acidic conditions in the presence of nonionic TX-100 as structure directors. These materials were characterized by XRD, HRTEM, N₂-adsorption, ²⁷Al MAS NMR, NH₃-TPD, IR-pyridine adsorption and catalytic cracking of cumene and 1,3,5-triisopropylbenzene. The experimental results showed that Al heteroatoms had been successfully incorporated into the framework structure of mesoporous MSU-X, and so-produced catalysts exhibited superior catalytic properties.     

Synthesis, Characterization, and Catalytic Properties of Chromium-Containing Hexagonal Mesoporous Aluminophosphate Molecular Sieves

Chromium-containing hexagonal mesoporous aluminophosphate molecular sieve materials were synthesized, characterized and evaluated for the oxidation of cyclohexane under mild conditions. The catalysts showed remarkable activity for the chosen reaction with very high substrate conversion and excellent product selectivity. In addition, recycling studies over the spent catalysts as well as studies on quenched solutions under the reaction conditions indicated no or very meager loss in activity; thus, the materials behaved truly as heterogeneous catalysts. This observation was well supported by ICP-AES analysis of the filtrates obtained from the washed catalysts where no leaching of active chromium species was detected. Furthermore, the reaction carried out using these filtrates confirmed the absence of active metal ions as it exhibited only a marginal activity.     

Fe-HMS的合成、表征及催化苯酚羟基化

以正硅酸乙酯(TEOS)、三氯化铁为原料,十二胺(DDA)为模板剂,采用溶胶-凝胶法合成了铁改性六方介孔硅分子筛(Fe-HMS),利用XRD、FTIR、UV-vis、ESR、TG-DTA、ESEM、TEM及N2吸附-脱附技术对材料结构进行了表征,同时以苯酚羟基化反应为探针考察了Fe-HMS的催化性能。结果表明,Fe-HMS材料由细小的球状纳米粒子组成,材料具有稳定的六方介孔结构,铁已进入六方介孔硅(HMS)载体的骨架;在苯酚羟基化反应中材料显示出较高的催化活性,苯酚的转化率最高可达46.9%,催化剂经450℃焙烧2 h即可再生,重复使用7次苯酚转化率仍可达36.4%。     

N—乙基间甲苯胺的催化合成

介绍以间甲苯胺和乙醇为原料,在铜锌铝氧化物催化剂上,在连续固定床反应器中合成Ｎ－乙基间甲苯胺,在常压,氢气气氛中,反应温２４０－２７０℃、醇／胺摩尔比１．２进料空速８－１２ｈ＾－１条件下,间甲苯胺的转化率≥９０％,生产Ｎ－乙基间甲苯胺的造反性为９０％－９５％。     

Recent Advances in the Synthesis and Catalytic Applications of Pillared Clays

New methods have been developed in recent years that are now being successfully applied in the preparation of pillared interlayered clays (PILCs). Variations in the procedures concern different parameters involved in the synthesis, such as the starting clay, the intercalating solution, the intercalation process, and the drying and calcination steps of the pillared solids, among others. In the present article, the latest results obtained when introducing modifications in the chemical aspects of PILC synthesis are reviewed. These include (1) pillaring with mixed solutions containing two or more cations, (2) using coordination or organometallic compounds, (3) using polymers and surfactants, (4) pillaring of acid-activated clays, and (5) enhancement of PILC acidity. A separate section is devoted to the specific features of preparing these solids in amounts large enough to make their manufacture on an industrial scale economically feasible. Recent developments in the catalytic applications of PILCs are also reviewed, with emphasis on the progressively more extended use of these materials as catalytic supports.     

磺酸基官能化介孔材料的表征及其催化性能

由高水热稳定的巯基官能化介孔硅基材料经氧化得到磺酸基官能化介孔固体酸催化剂。经过一系列的表征测试,所得固体酸具有发达的孔道结构和大量Br尴nsted酸性位。将其应用于苯甲醛与醇类缩合反应中,与传统沸石固体酸催化剂HY相比,显示了更好的催化性能,缩醛收率在90%左右。所合成的磺酸基官能化介孔固体酸催化剂的催化性能基本不受醇类分子体积影响,具有很好的重复使用性能。     

Recent Advances in the Synthesis and Catalytic Applications of Pillared Clays

New methods have been developed in recent years that are now being successfully applied in the preparation of pillared interlayered clays (PILCs). Variations in the procedures concern different parameters involved in the synthesis, such as the starting clay, the intercalating solution, the intercalation process, and the drying and calcination steps of the pillared solids, among others. In the present article, the latest results obtained when introducing modifications in the chemical aspects of PILC synthesis are reviewed. These include (1) pillaring with mixed solutions containing two or more cations, (2) using coordination or organometallic compounds, (3) using polymers and surfactants, (4) pillaring of acid-activated clays, and (5) enhancement of PILC acidity. A separate section is devoted to the specific features of preparing these solids in amounts large enough to make their manufacture on an industrial scale economically feasible. Recent developments in the catalytic applications of PILCs are also reviewed, with emphasis on the progressively more extended use of these materials as catalytic supports.     

聚对苯二甲酸丙二醇酯的合成及表征

采用直接酯化缩聚合成工艺自制新型树脂—聚对苯二甲酸丙二醇酯（ＰＴＴ） 。详细讨论了聚合条件对合成反应的影响。用红外光谱、核磁共振分析表征了ＰＴＴ 的结构,并将结果同ＰＢＴ和ＰＥＴ 作了比较。研究结果表明在酯化反应转化率达到８０ ％ 左右开始进行缩聚反应有利于减少副产物,同时也不会影响制得合格的ＰＴＴ 树脂：在ＰＢＴ 大分子链节中的（ － ＣＨ２） 数是ＰＥＴ 的２ ．０４ 倍,是ＰＴＴ 的１．３４ 倍;ＰＴＴ 大分子链节中的（ － ＣＨ２） 数是ＰＥＴ 的１ ．５２ 倍。因此ＰＴＴ 大分子链的柔顺性在ＰＢＴ 和ＰＥＴ 之间     

离子液体分类、合成、表征及应用研究

离子液体作为一种新型的环境友好溶剂和液体酸催化剂,具有众多优点。其结构和酸性具有可调性,催化剂和产物容易分离,高热稳定性,是真正意义上可设计的绿色溶剂和催化剂。介绍了离子液体的分类、合成和表征方法。综述了离子液体在化学化工领域中的应用进展并展望其前景。     

乙酰乙酸酯的合成及表征

本文以双乙烯酮与各种醇反应得到了12种乙酰乙酸酯,并通过沸点、折光率和红外光谱对这些化合物进行了确认。