聚合物生物碱相转移催化剂的合成及其对多类化学反应的催化性能

聚合物生物碱相转移催化剂的合成及其对多类化学反应的催化性能黄锦霞，陈家威，蒋济隆，卢军（湖北大学化学系，武汉４３００６２）（广西师范大学化学系，南宁５３０００１）关键词相转移催化剂，聚合物，生物碱，三相催化，不对称反应相转移催化反应是有机合成中较为活...     

相转移法制备Cu—Cr甲酸甲酯加氢合成甲醇催化剂

用戊酸铜作金属表面活性剂相转移制备了Ｃｕ－Ｃｒ合成了甲醇催化剂。结果发现相转移制备的产物具有与共沉淀法制备的催化剂不同的晶相结构，其粒子也要小得多，表面覆盖式Ｃｕ－Ｃｒ催化剂程序升温还原后表面主要为Ｃｕ。用于由甲酸甲酯加氢制甲醇的活性显著高于共沉淀催化剂，。其选择性近似１００％。     

聚苯乙烯树脂固载聚乙二醇及吡啶weng盐的合成及其活性评价

以氯甲基化聚苯乙烯为原料，先后接枝聚乙二醇及吡啶，合成了双中心固载相转移催化剂──交联聚苯乙烯固载聚乙二醇４００及吡啶weng盐，并对氯甲基化聚苯乙烯树脂、聚苯乙烯固载聚乙二醇树脂、聚苯乙烯固载吡啶weng盐树脂及双中心树脂进行了红外光谱测试和分析，通过醋酸钾与溴节的反应，对各催化剂进行了活性评价，发现固载双中心相转移催化剂的活性明显高于各单中心固载相转移催化剂。     

聚苯乙烯树脂固载聚乙二醇及吡啶翁盐的合成及其活性评价

以氯甲基化聚苯乙烯为原料，先后接枝聚乙二醇及吡啶，合成了双中心固载相转移催化剂－交联聚苯乙烯固载聚乙二醇400及吡啶翁盐，并对氯甲基化聚苯乙烯树脂、聚苯乙烯固载聚乙二醇树脂、聚苯乙烯固载吡啶翁盐树脂及双中心树脂进行了红外光谱测试和分析。通过醋酸钾与溴苄的反应，对各催化剂进行了活性评价。发现固载双中心相转移催化剂的活性明显高于各单向中心固载相转移催化剂。     

新型相转移催化剂的合成及其催化水解反应研究

相转移催化(PTC)技术是70年代初发展起来的应用在有机合成中的新技术。由于相转移催化剂能使反应速度加快,产率明显提高,反反化学通报1,2年第,期此,近年来相转移催化这一技术发展很快。高分子相转移催化剂,由于它具有在反应完毕后容易分离     

强碱离子交换树脂催化剂在有机合成中的应用

本文综述了近年来强碱阴离子交换树脂及其支载的高分子催化剂在相转移反应，缩合，加成反应，氧化还原，酯交换，水解等反应中的应用应用。     

0聚合物固载的聚乙二醇季铵盐型相转移催化剂的合成,表征及相…

合成了一系列含有聚乙二聚链和季铵盐两种性中心的离分子相转移催化剂，并考察了它闪在正溴辛烷与固体碘化钠的亲核了以代反应中的相转移催化性能。     

环己酮合成实验的改进

对环己酮的合成实验进行了改进。以WO3为催化剂、H2O2为氧化剂、四丁基溴化铵（TBAB）为相转移催化剂,催化氧化环己醇制备环己酮。确定了催化剂、氧化剂和相转移催化剂的用量,并研究了反应温度和时间等条件对反应的影响。     

键联聚乙二醇高分子担载锰（Ⅲ）卟啉的合成及催化烯烃环氧化反应性…

本文研究了键联聚乙二醇高分子担载锰（Ⅲ）卟啉的合成，以及在ＣＨ２Ｃｌ２／Ｈ２Ｏ两相体系中催化苯乙烯环氧化反应的性能，探索了催化反应体系中溶液ｐＨ值、ＮａＯＣｌ浓度、轴向配体及相转移催化剂对催化反应的影响。结果说明键联聚乙二醇高分子担载锰（Ⅲ）卟啉是烯烃环氧化反应的一种有效催化剂，其中聚乙二醇链可以络合Ｎａ，使ＯＣｌ富集于金属卟啉周围，起到较好的相转移催化作用。在催化反应的各影响因素中，水相ｐＨ值对     

聚合物固载相转移催化剂在有机合成中的应用

本文综述了聚合物固载相转移催化剂在有机合成中的应用，包括亲核取代反、应、加成反应。消除反应、氧化还原反应等。     

Investigation of catalytic activities by differential thermal analysis

A calorimetric method is proposed to evaluate the catalytic activity of a solid catalyst with respect to the exothermic oxidation of Volatile Organic Compounds (VOC).This method employs a differential thermal analyzer in which an inert reference and a catalytically active sample are both fluxed at a constant rate with a reactive gaseous mixture composed of an inert gas (N₂ 90% vol.), oxygen and VOC, the last typically 900 to 5000 ppm. While the temperature is varied according to a predefined cycle, the output signal due to the exothermic reaction on the catalyst is continuously recorded. The design of the test chamber, the amount of catalyst, the shape of the holders and finally the flow rate and composition of the gaseous mixture should be carefully selected in order to achieve reproducible results.     

负载型钯催化剂用于不饱和化合物的加氢反应

近十多年来,均相络合催化剂的固载化是一个活跃的研究领域^[1-6],我们在聚合、歧化、加氢等络合催化剂负载化方面的工作^[7-9]。说明负载型络合催化剂中的载体,可以视为一个配体,由于其有不同的化学及空间效应,因此是一个复杂的配体.在环戊二烯选择加氢的研究中,不同载体对加氢反应的活性及选择性的影响,说明载体的性质、结构、分子量及其上基团,对于底物的配位和它在活性物种上的加氢速度常数都有调变作用^[10],本文报道固载化络合催化剂在多种不饱和烃加氢反应中的行为.     

多相催化体系的反应机理和失活模式(英文)

Solving the problem of catalyst deactivation is essential in process design. To do this, various aspects of the kinetics of processes with catalyst deactivation, and their different mechanisms, are discussed. Catalyst deactivation often cannot be avoided, but more knowledge on its mechanism can help to find kinetic means to reduce its harmful consequences. When deactivation is caused by coke, the generation of coke precursors is the determining step in the deactivation kinetics. Different types of deactivation were distinguished that lead to different evolution of the process. The phenomenon of non-uniform coking can be linked to catalyst surface non-uniformity. For the class of catalysts with more than one type of active sites, an explanation was suggested for the observed trends in the deactivation modes. For catalytic proc-esses using catalyst particles of industrial size, the influence of intraparticle diffusion resistance is important. The analysis showed that for a number of processes, the decrease of the reaction rate due to deactivation is less under diffusion control. For certain reaction mechanisms, there exist operation conditions where the rate of the process under diffusion control exceeds the rate in the kinetic control regime. A signifi-cant problem is the change of selectivity in the course of catalyst deactivation. The selectivity may either decrease or increase, and depends on the reaction mechanism during deactivation. The changes are larger when there is no diffusion resistance. The intentional poisoning of catalysts and its influence on catalyst activity and selectivity for the process of ethylene oxide production was discussed.     

Ba(OH)2 as catalyst in organic reactions,IV. Reaction between coumarin and diethyl malonate

The reaction of diethyl malonate and coumarin catalyzed by an activated barium hydroxide catalyst (C-200) in a solid-liquid-system is described. NoMichael addition takes place. An unusual nucleophilic addition-elimination process to the C=O bond of coumarin is observed and the new compound is described the first time. The process is explained by the microcrystalline structure of the solid, the nature of the active sites of the catalyst and the chelating action of coumarin on Ba^II of the lattice.

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Ba(OH)₂ als Katalysator organischer Reaktionen, 4. Mitt.: Die Reaktion zwischen Cumarin und Diethylmalonat

Zusammenfassung Es wird die Reaktion von Diethylmalonat mit Cumarin unter der katalytischen Wirkung von aktiviertem Bariumhydroxid (C-200) in einem Fest-flüssig-System beschrieben. Es ist keineMichael-Addition zu beobachten. Es tritt eine ungewöhnliche Addition-Eliminierung an der C=O-Bindung des Cumarin ein und die dabei entstehende Verbindung wird erstmals beschrieben. Der Prozeß wird auf der Basis der mikrokristallinen Struktur des Festkörpers, der Natur der aktiven Stellen am Katalysator und der chelierenden Wirkung von Cumarin auf die Gitter-Ba^II-Ionen erklärt.

     

Recycling Functional Colloids and Nanoparticles

The stability and separation of colloids and nanoparticles has been addressed in numerous studies. Most of the work reported to date requires high cost, energy intensive approaches such as ultracentrifugation and solvent evaporation to recover the particles. At this point of time, when green science is beginning to make a real impact, it is vital to achieve efficient and effective separation and recovery of colloids to provide environmental and economic benefits. This article explores recent advances in strategies for recycling and reusing functional nanomaterials, which indicate new directions in lean engineering of high‐value nanoparticles, such as Au and Pd.     

合成氨催化剂研究的新进展

 近20多年来,随着英国BP公司钌基催化剂的发明和我国亚铁基熔铁催化剂体系的创立,标志着合成氨催化剂进入了一个新的发展时期,由唯一的传统Fe3O4路线发展为三条技术路线,并各自取得了重大进展．本文扼要介绍了Fe3O4基传统催化剂和钌基催化剂的主要研究成果和发展趋势,着重综述了我国独创的Fe1－xO基熔铁催化剂的发现及其高活性机理探讨方面的研究成果．回顾了20世纪合成氨工业及其催化剂从创立、发展,到取得辉煌成就的历程,展望了21世纪的发展趋势．     

A new tetrasubstituted α-fluoro cyclohexanone bearing a fluoroisopropyl group at C5

A new tetrasubstituted cyclohexanone 5 fluorinated at C2 and having a fluoroisopropyl group at C5 has been synthesized in five steps from 3-methyl cyclohexenone and the structure of both diastereomers fully assigned. It is shown that diastereomer Ia having the fluorine atom at C2 in the axial position (in the most populated conformer of this diastereomer) is major and is a good catalyst for epoxidation of trans-olefins by oxone while diastereomer IIe is not. Moreover, only 0.3 equiv. of 5-Ia are necessary and the ketone is totaly recovered after reaction (no Baeyer-Villiger).     

Dimerization of Acetylene to Monovinylacetylene (MVA) by Bimetallic Zr/Cu Catalyst in Nieuwland Catalytic System

Nieuwland catalyst is a key step in the dimerization of acetylene. Various zirconium metal additives incorporating Nieuwland catalysts were prepared, and their catalytic performances were assessed in acetylene dimerization. Different characterization techniques (i.e., thermogravimetric analysis, temperature-programmed reduction, X-ray diffraction, X-ray photoelectron spectroscopy, hydrogen ion concentration measurement and transmission electron microscopy) were employed in this study. The best catalytic performance was obtained over zirconium-acetylacetonate-incorporated Nieuwland catalysts, with an acetylene conversion of 53.3% and a monovinylacetylene selectivity of 87.4%. Based on these results, the zirconium acetylacetonate additive could reduce the types of transition state complexes, and it could also change the morphology of the catalyst. In addition, the additives could significantly inhibit the occurrence of trimerization products and polymers. Hence, the conversion of acetylene, monovinylacetylene selectivity, and stability of the Nieuwland catalysts were enhanced.     

汽车尾气净化用钯催化剂的制备及活性考察

制备了一系列用于净化汽车尾气的新型钯催化剂．该催化剂以堇青石蜂窝陶瓷为基体与含助剂的γ-Al2O3涂覆层构成载体，La、Ce、Pr、Sm、Nd、Eu、Mg、Ca、Ba、Sr、Ni、Fe、Mn等的复合氧化物为助催化剂，主活性组分钯，含量为0．05％．在实验室配气条件下，对该系列催化剂进行三效活性的测试，结果显示催化剂对CO．THC．NO的T50分别为188℃，213℃，204℃，经空气中1000℃／4h的快速热老化后(相当于汽车运行5万公里)，T50分别为202℃，231℃，222℃；表明，部分助剂引入涂层，增大了载体的比表面积，提高了载体的抗热冲击能力；以氧化物形式引入的另一部分助剂同时起到分散和稳定贵金属的作用，且钯与其产生协同作用，对改善钯催化剂的三效性能有显著效果．     

Regeneration of Pd/Al2O3 catalysts used for tetrachloroethylene hydrodechlorination

The deactivation of the Pd/Al₂O₃ catalyst used for the hydrodechlorination of tetrachloroethylene (TTCE) is caused by both the carbonaceous deposits and by the hydrogen chloride produced in the reaction. In this work, several regeneration procedures have been tested, concluding that the best procedure is the leaching with ammonia, followed by calcinations and reduction. This procedure leads to an important recovery of the initial activity. The catalyst regenerated with this treatment is even less prone to deactivation that the fresh catalyst.