双重负载钯催化剂用于硝基化合物的催化加氢

将可溶的聚乙烯吡咯烷酮负载的钯催化剂进一步负载到γ－Ａｌ２Ｏ３上，得到双重负载的钯催化剂。在少量碱的存在下，这种双重负载的钯催化剂在常温常压下对硝基苯的催化加氢表现出非常高的活性。γ－Ａｌ２Ｏ３负载的聚乙烯吡咯烷酮钯催化剂［ＰＶＰ－Ｐｄ／Ａｌ２Ｏ３（ｍｅｔｈｏｄＢ）］对硝基苯和ｐ－甲基硝基苯加氢的ＴＯＦｍａｘ（ｍａｘｉｍｕｍｔｕｒｎｏｖｅｒｆｒｅｑｕｅｎｃｙ，ｎ（Ｈ２）／（ｎ（Ｐｄ）．ｔ）），分别     

甲酸为氢源的甘油催化选择氢解

以甲酸作为氢源, 采用铜基复合金属氧化物催化剂, 催化氢解甘油制备1,2-丙二醇, 其中液相甲酸的高选择性分解是实现甘油氢解的必要和关键步骤. 活性测试表明, 高分散的铜和ZrO₂载体间的协同作用对甲酸分解和甘油到1,2-丙二醇的转化至关重要, 20%Cu/ZrO₂催化剂的活性最佳. 由于避免使用相对昂贵的化石燃料氢, 因而该催化体系在生物质的高值利用方面具有潜在的应用前景.     

芳香硝基化合物原位液相加氢一锅法合成喹啉类化合物

以芳香硝基化合物为起始原料,以2%Pt-Sn/γ-Al2O3为催化剂,采用原位液相加氢法可以一锅法合成喹啉类化合物,考察了Pt/Sn摩尔比、反应温度、原料浓度和水含量等对反应性能的影响.结果表明,在Pt/Sn摩尔比0.5,220oC,5.0MPa,原料浓度6%,水含量30%及反应物停留时间为72s的条件下,生成产物6-甲氧基-2-甲基喹啉的收率可达72%.     

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.     

络合还原法制备碳载钯纳米粒子及其电催化甲酸氧化

应用柠檬酸钠络合还原法制备了粒径小、分布均匀的碳载Pd纳米粒子(Pd/C).由于柠檬酸钠的络合作用,有效地降低了Pd粒子在形成过程中的团聚.经过简单的热处理调控Pd粒子大小,发现随热处理温度的升高,Pd粒子直径由初始的2.7 nm增大到5.8 nm左右.电化学测试表明Pd/C的Pd粒子尺寸越小,电催化甲酸氧化的质量比活性越高,但如当Pd粒径较大,则催化剂呈现出更高的面积比活性.Pd粒径为3.6 nm的催化剂,其电催化甲酸氧化的稳定性最好.     

钯／阴离子交换树脂对硝基化合物催化加氢的取代基效应

本文研究了聚苯乙烯系强碱性阴离子交换树脂负载的钯催化剂对取代硝基苯催化加氢的性能,结果表明,取代基的电子性质及空间位置对加氢速率影响很大;反应活化能与取代常数σ之间呈线性关系:E_1=-20.7σ+47.0在该反应体系中存在补偿效应:log A_(red)=0.14E_a-6.86     

β-榄香烯的钯、铑催化加氢反应研究

β榄香烯是我国首创的抗癌新药榄香烯乳注射液的主要成分［１］,它的结构是在甲基环己烷骨架上连接有３个烯基取代基（１个乙烯基和２个异丙烯基）．研究β榄香烯３个双键上的化学反应活性,对于榄香烯新反应的开发以及榄香烯类化合物构效关系的研究具有很重要的意义...     

高分子钯络合物催化的亚胺化合物的加氢反应

制备了一系列以二氧化硅为载体的侧链上含有各种氮配位基团的聚硅氧烷-钯络合物,这些高分子钯络合物能够在常温常压下催化亚胺化合物的加氢反应并表现出不同程度的催化活性.对其中聚-(N,N-二乙酰基)-γ-氨丙基硅氧烷-钯络合物催化的亚苄基苯胺的加氢反应做了比较深入的研究,发现该催化剂在反应中是稳定的并给出唯一的加氢产物,络合物中的N/Pd原子比、反应温度以及不同底物对反应速度的影响也被报道.     

非晶合金NiB催化芳环及硝基的加氢性能

催化氢化;非晶合金NiB催化芳环及硝基的加氢性能     

聚席夫碱钯（Ⅱ）配合物对芳香族硝基化合物加氢反应的催化性能

以交联聚席夫碱钯的配合物作为催化剂，对芳香族硝基化合物催化加氢性能进行了研究。该催化剂在常温、常压下可使硝基苯１００％催化氢化为苯胺。对某些芳香族硝基化合物转化为相应胺的产率也可达９０％以上。此催化剂性能稳定，重复使用８０次仍具有一定催化活性。     

Agglomerated Pd Catalysts and Their Applications in Hydrogen Production from Formic Acid Decomposition at Room Temperature

Agglomerated Pd catalysts with the nano-porous structure were simply prepared by one-step reduction reaction without using any stabilizer. The Pd catalysts show a high catalytic activity for the decomposition of formic acid at room temperature. Among all the Pd catalysts tested, the Pd_Mg catalyst exhibits the highest catalytic activity. Moreover, the breakthrough of the advanced catalysts is that the above agglomerated Pd catalysts can be easily separated from the liquid system to control the catalytic reaction at any time, which may further promote the practical application of formic acid as a H₂ storage material.     

Water-Soluble Ligands,Metal Complexes,and Catalysts: Synergism of Homogeneous and Heterogeneous Catalysis

Rapid developments in the field of catalysis are leading to an increased demand for tailor-made catalysts. Water-soluble complex catalysts, which are being intensively investigated at the present time, combine the advantages of homogeneous and heterogeneous catalysis: simple and complete separation of the product from the catalyst, high activity, and high selectivity. From the large number of available water-soluble ligands, the appropriate catalysts can be developed for many reactions. The industrial applications in the fields of hydrogenation and hydroformylation have already indicated the wide scope of this type of catalyst. In addition, the annual production of 300 000 tons of butyraldehyde through application of water-soluble rhodium complexes at Hoechst AG in Oberhausen, Germany, has demonstrated the industrial importance of the concept of complex-catalyzed reactions in aqueous two-phase systems. The efficient operation of catalytic processes increasingly requires the loss-free recycling of the noble metal catalyst, and this can be simply and economically realized in two-phase systems. Special applications in biochemical problems open up developments in the field of water-soluble transition metal complexes that far transcend the familiar kinds of homogeneous catalysis. In the near future, the investigation and application of metal complex catalysts that are compatible with the physiological, cheap, and environmentally friendly solvent, water, is likely to become a high priority in catalysis research.     

Preparation of Ultrafine and High Dispersion Pd/C Catalyst and Its Electrocatalytic Performance for Formic Acid Oxidation

A carbon supported Pd(Pd/C) catalyst used as the anodic catalyst in the direct formic acid fuel cells(DFAFC) was prepared via the improved complex reduction method with sodium ethylenediamine tetracetate(EDTA) as stabilizer and complexing agent.This method is very simple.The average size of the Pd particles in the Pd/C catalyst prepared with the improved complex reduction method is as small as about 2.1 nm and the Pd particles in the Pd/C catalyst possess an excellent uniformity.The Pd/C catalyst shows a high electrocatalytic activity and stability for the formic acid oxidation.     

Design and Synthesis of Heterogeneous Frustrated Lewis Pairs for Hydrogenation: From Molecular Immobilization to Defects Engineering

The concept of “Frustrated Lewis pairs” (FLPs), which emerged from the discovery that H₂ can be reversibly activated by combinations of sterically encumbered Lewis acids and bases. Since then, the field of FLP chemistry has expanded enormously. One of the most remarkable achievements is the development of FLP catalysts for hydrogenation, which are environmentally friendly and have potential industrial application prospects. In recent years, this unique catalysis concept has pushed the study of FLP chemistry to a new direction: heterogeneous FLP catalysts. This review outlines the recent research progress of new strategies to design and synthesize heterogeneous FLPs for hydrogenation reaction, and prospects the development of novel heterogeneous FLP catalysts.     

直接甲酸燃料电池炭载Pd阳极催化剂的稳定性

用X射线衍射和电化学方法研究了在甲酸溶液中浸泡一段时间后的Pd/C催化剂的结构和电催化性能, 发现在甲酸溶液中浸泡15 d后, Pd/C催化剂中Pd粒子的相对结晶度由1.73增加到3.34, 平均粒径由4.4 nm降低到1.8 nm, 对甲酸氧化的电催化活性和稳定性降低, 甲酸氧化的峰电流密度由9.3 mA/cm2降低到6.7 mA/cm2. 这可能是由Pd/C催化剂中的Pd在甲酸中会有一定的溶解和Pd/C催化剂能催化分解甲酸引起的.     

直接甲酸燃料电池Pd阳极催化剂及其电催化稳定性

直接甲酸燃料电池(DFAFC)中Pd阳极催化剂对甲酸氧化具有很好的电催化活性, 但电催化稳定性较差, 因此, 对Pd催化剂电催化活性和稳定性的影响原因和机理的研究已经成为DFAFC阳极催化剂的研究重点, 本文综述了DFAFC中Pd催化剂和Pd基复合催化剂的研究和发展概况. 主要介绍了Pd催化剂的优缺点、稳定性及提高稳定性的方法和机理等, 为Pd催化剂和Pd基复合催化剂的实际应用奠定基础.     

Heterogeneous borrowing hydrogen reactions with Pd/C and ZnO: Diol scope

A borrowing hydrogen reaction with different diols was employed for the preparation of complex beta- gamma- or epsilon-amino alcohols from p-toluidine and tetrahydroquinoline with the aim of better understanding the applicability of the Pd/C ZnO heterogeneous catalyst.     

二氧化碳加氢制甲醇多相催化剂研究进展

化石燃料的利用为人类社会带来了前所未有的繁荣和发展. 然而, 化石燃料燃烧引起的过量的二氧化碳(CO₂)排放导致全球气候变化和海洋酸化; 而且作为一种有限的资源, 化石燃料的消耗将迫使人们寻找其它碳源以维持可持续的发展. 利用可再生能源获取电能分解水制得的绿色氢气(H₂)与捕集后的CO₂反应制成甲醇, 不仅能有效利用工业废气中多余的CO₂, 还能获取清洁、 可再生的甲醇化学品, 该过程的技术核心是开发高效稳定的CO₂加氢制甲醇催化剂. 本文综合评述了现有研究关注较多的多相催化CO₂加氢制甲醇催化剂的反应机理和构效关系, 总结了目前多相催化CO₂加氢制甲醇催化剂(Cu基催化剂、 贵金属与双金属催化剂、 氧化物催化剂以及其它新型催化剂)的设计与合成方面的研究进展, 最后对该领域所面临的机遇和挑战进行了展望.     

二氧化碳多相催化加氢制C2及以上烃类和醇的研究进展

通过可再生能源得到的氢气将二氧化碳转化为高附加值的燃料和化学品,对于缓解全球变暖、改善生态环境和解决化石资源日益枯竭的难题具有重要的意义。通过加氢反应合成碳氢化合物,尤其是C₂₊烃类和含氧化合物愈来愈引起大家的研究兴趣。设计制备兼具二氧化碳活化和碳-碳键耦合的多功能催化剂仍然是一较大的挑战。本文总结了二氧化碳加氢合成长链烷烃、低碳烯烃、高级醇的最新研究进展,探讨了二氧化碳加氢所涉及的相关反应的热力学和动力学、反应机理和反应路径,并对现阶段报道的多相催化剂进行了归纳和分析,最后指出未来在二氧化碳加氢的多相催化过程中所面临的问题和发展方向。     

Hydrogenation of vermistatin

Summary Hydrogenation of vermistatin, a metabolite ofPenicillium vermiculatum, affordedcis- andtrans-3-(2-carboxy-4,6-dimethoxybenzyl)-6-propyltetrahydro-4H-pyran-4-one and 4,6-dimethoxy-3-(4-propylcyclopentanon-2-yl)phthalide. The latter compound was found to be the strongest inhibitor of RNA synthesis in P 388 leukemia cells of all compounds tested.

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Hydrierung von Vermistatin

Zusammenfassung Bei der Hydrierung von Vermistatin, einem neuen sekundären Metabolit ausPenicillium vermiculatum, wurdencis- undtrans 3-(2-Carboxy-4,6-dimethoxybenzyl)-6-propyltetrahydro-4-pyran-4-on und 4,6-dimethoxy-3-(4-propylcyclopentanon-2-yl)phthalid erhalten und spektroskopisch charakterisiert. Die letztgenannte Verbindung zeigte von allen getesteten Verbindungen die stärkste Hemmwirkung auf die RNA Synthese in P 388 Leukämiezellen.