新型水溶性配体-负载金属氢甲酰化催化剂:TPPTS-Rh/SiO2

考察了几种硅胶负载贵金属催化剂和HRhCO(TPP)3催化剂的1-己烯氢甲酰化反应,对Rh/SiO2、 HRhCO(TPPTS)3/SiO2 和TPPTS-Rh/SiO2上的1-己烯氢甲酰化结果进行了比较.结果表明, TPPTS-Rh/SiO2催化剂的醛的选择性和醛的正异比n/b接近HRhCO(TPPTS)3/SiO2 的相应的催化性能,而远高于Rh/SiO2的相应的催化性能, 7.0 MPa高压下TPPTS-Rh/SiO2催化剂的活性大幅度增加,达到0.0692 S-1.实验排除了其他可能,认为是含有孤对电子的TPPTS 和Rh/SiO2中高度分散的Rh粒子产生了化学键的作用,形成了具有匀相性能的支撑水膜多相催化剂: TPPTS-Rh/SiO2.     

结构助剂SiO2、Al2O3对铁基催化剂浆态床F-T合成性能的影响

采用连续共沉淀与喷雾干燥成型技术相结合的方法制备了微球状Fe/Cu/K/SiO2和Fe/Cu/K/Al2O3催化剂，研究SiO2和Al2O3作为结构助剂对铁基催化剂吸附行为、炭化行为及F-T合成反应性能的影响。表征结果表明,与Al2O3相比较，SiO2抑制了H2的吸附，但促进了CO的吸附，有利于催化剂的炭化。催化剂在260℃、1.5MPa、H2/CO=0.67和2000h-1下的浆态床F-T合成反应评价表明，Fe/Cu/K/SiO2催化剂具有较高的F-T合成活性、高的水煤气变换反应（WGS）活性，且其烃产物选择性明显向高炭数方向偏移，而Fe/Cu/K/Al2O3催化剂则表现出较低的F-T合成活性、低的水煤气变换反应（WGS）活性和高的轻质烃选择性。但Fe/Cu/K/Al2O3催化剂比Fe/Cu/K/SiO2催化剂具有更好的运行稳定性。     

Pd-Sn-K/SiO2催化剂上甲苯气相氧乙酰化反应

 在常规固定床流动反应体系中研究了Pd-Sn-K/SiO2催化剂上气/固相氧化条件下甲苯与乙酸一步合成乙酸苄酯的反应. 结果表明,金属态钯是催化甲苯氧乙酰化合成乙酸苄酯的高活性组分,锡化合物的存在可明显提高催化剂的活性. 催化剂的活性与制备方法密切相关,用H2将SiO2上负载的钯化合物还原之后再负载锡化合物所得催化剂的活性较高. XRD分析结果表明,钯还原前负载锡化合物所得催化剂的活性大幅度降低的原因在于Pd和Sn形成了金属间化合物. 使用Pd/SiO2质量比为0.015, K∶Sn∶Pd摩尔比为27∶3∶1的Pd-Sn-K/SiO2催化剂,在反应温度为180 ℃,混合原料气甲苯∶乙酸∶氧气∶氮气摩尔比为1∶4∶1∶4以及空速为 1680 h-1的条件下,甲苯转化率可达25.3%, 乙酸苄酯选择性为91%. 以TiO2和ZrO2代替SiO2载体,或以其它变价金属氧化物代替Sn氧化物助剂或金属钯,均未发现有更好的催化效果.     

SiO2负载MoVNbO复合氧化物催化剂上乙烷低温氧化制乙酸

 采用有机金属络合物浸渍表面反应技术制备了SiO2为载体的复合氧化物催化剂Mo3V1Nb0.3Ox/SiO2,并用N2吸附,IR,UV-Vis,TPR和微反技术研究了催化剂的表面结构、晶格氧的活性和对乙烷选择氧化反应的性能. 实验结果表明,复合氧化物与SiO2表面以M-O-Si键连接,金属离子处在四面体和八面体配合物结构之中;含铌的表面复合氧化物中晶格氧的活性明显提高. 在252 ℃,0.5 MPa和空速 2000 h-1的反应条件下,乙烷与氧在Mo3V1Nb0.3Ox/SiO2催化剂上发生反应,生成乙酸和乙醛,乙烷的转化率达16.1%,产物乙酸和乙醛的总选择性为90.3%.     

Fe、Co组成对Cu-Fe-Co基混合醇催化剂合成性能的影响

采用共浸渍法制备了一系列不同Fe、Co组成的Cu-Fe-Co基混合醇催化剂,对其CO加氢合成混合醇反应性能进行了考察,并采用BET比表面积分析、X射线衍射（XRD）、X射线光电子能谱（XPS）、场发射扫描电子显微镜（FE-SEM）及H₂程序升温还原（H₂-TPR）等手段对其进行了表征.结果表明:Cu-Fe二元催化剂添加适量的Co可以明显提高催化剂醇的明空收率（STY）、CO转化率,而总醇选择性不变.当活性组分Cu、Fe及助剂Co的质量分数分别为25%、22%、3%时,催化剂醇的时空收率高达205.6 g·kg^-1·h^-1,CO转化率为56.6%.XRD、XPS和TPR结果表明:在Cu组分含量不变时,少量Co组分的引入使催化剂表面形成微量的CuFe₂O₄相,促进了Cu-Fe组分间相互作用的增强,改善了催化剂活性组分的分散度,有利于提高催化剂活性及醇的时空收率;随Co含量的增大,催化剂中金属组分间的相互作用发生转变,形成了Cu-Co尖晶石相,导致催化剂的醇选择性有所下降.     

锰和镧改性Cu/ZrO2合成甲醇催化剂的结构及催化性能

 考察了锰和镧助剂对Cu/ZrO2催化剂上CO加氢合成甲醇反应性能的影响,并通过BET,XRD,TPR,H2-TPD和CO-TPD等手段对催化剂的结构及吸附-脱附性能进行了研究. 结果表明,锰和镧两种助剂均能有效地提高催化剂的活性,同时引入两种助剂时可使催化剂的活性进一步提高,表现出较强的协同效应. 一方面,锰的加入可使催化剂各组分的相互作用增强,特别是铜锰复合物的形成可有效地促进活性组分的分散,防止催化剂的烧结; 另一方面,镧助剂的引入进一步增强了铜锆在界面的相互作用,稳定了催化剂的活性中心,有利于吸附物种在两者之间发生溢流.     

合成气制低碳混合醇耐硫钼基催化剂的制备研究

本文考察了不同制备方法和制备程序制得之MoSx-K^ /Si O2催化剂对合成转化为低碳混合醇的催化性能，探讨不同助剂（包括K2 CO3，KF，DC1等）对催化剂活性和选择性的影响，首次报道以K2MoS4作为前驱物料制得的MoSx-K^ /SiO2催化剂具有与（NH4）2MoS4- K2CO3/SiO2和法生得到的催化剂几乎一样高的催化活性 和选择性 ，其结果为具有实用意义的催化剂的研制提供依据。     

CO和NO在Rh2-V/SiO2催化剂上共吸附的红外光谱

应用CO和NO吸附态原位红外光谱方法研究了还原态Rh2／SiO2，Rh2－V／SiO2催化剂上的活性中心铑的状态和助剂钒的作用. Rh2催化剂用Rh2（CO）4Cl2化合物制备. 在还原Rh2／SiO2催化剂上，CO吸附出现四个红外吸收峰：2085，2028cm－1（孪生态吸附RhⅠ（CO）2），2060cm－1（线式吸附RhⅡCO），1867cm－1（桥式吸附RhⅢ2CO）．在还原Rh2－V／SiO2催化剂上，CO在RhⅡ和RhⅢ中心上的吸附峰大大减弱，可以解释为Rh°向钒离子转移电子生成了带正电荷的铑中心（Rhδ＋）；同时RhⅠ（CO）2键能增加，降低了孪生CO被NO置换的程度。     

溶胶-凝胶法制备负载磷钼杂多酸铵催化苯硝化反应

以正硅酸乙酯为硅源,利用溶胶-凝胶法制备负载磷钼杂多酸铵催化剂（AMPA/SiO2）,采用X射线衍射和红外光谱测试技术对催化剂进行了表征,并初步评价了催化剂苯硝化反应催化性能。结果表明,溶胶-凝胶法制备的AMPA/SiO2保持了磷钼酸铵（AMPA）杂多酸盐的Keggin结构。AMPA以及AMPA/SiO2催化剂均表现出较强的苯硝化反应催化活性和100 ％的一硝基苯选择性,苯最高转化率为96 ％。反应后负载催化剂活性组分有所损失,但催化剂整体物相和结构没有发生明显变化。     

MoP/SiO_2-TiO_2-ZrO_2加氢脱硫催化剂的研制

采用共沉淀法制备了SiO2-TiO2-ZrO2复合载体,并用共浸渍法制备了负载型MoP/SiO2-TiO2-ZrO2催化剂,通过H2原位还原技术对催化剂进行还原处理,在小型连续固定床反应器上进行催化剂的加氢脱硫活性评价。结果表明,SiO2-TiO2-ZrO2复合载体为介孔材料,MoP/SiO2-TiO2-ZrO2比一元及二元载体催化剂的加氢脱硫活性提高了12-31%;Si/Ti/Zr摩尔比以及MoP的负载量对催化剂的活性有很大影响,当n(Si)/n(Ti)/n(Zr)=0.163/0.809/0.028、MoP的负载量为20%时,催化剂的加氢脱硫效果最好:在380℃、压力4.0 Mpa、空速6 h(1、氢油比500条件下,二苯并噻吩的转化率达到了99.1%。     

担载型铑络合物催化异丁烯氢甲酰化反应的研究

将铑络合物担载于磷钨酸改性的载体上制备了一系列新型催化剂。利用异丁烯氢的甲酰化反应考察了磷钨酸改性的各种载体对催化剂的活性和稳定性的影响。结果表明,以磷钨酸改性的S iO2为载体的催化剂在反应中的催化效果最好,当异丁烯5.0 g,V(H2)∶V(CO)=1∶1,p=3.0 MPa时,于377 K反应5 h,ASTY达420.9 h-1;异戊醛的收率为80.37%。     

Kinetics of Ethylene Oxidation on a Supported Silver Catalyst

The kinetics of ethylene oxidation by air over a supported silver catalyst were investigated in the temperature range 490–620 K. The reaction network was found to be triangular. Under virtually constant oxygen partial pressure (0.2 bar), the following rate relationships, (in mol g^?1s^?1) were found: (formulae in curved brackets denote partial pressures) where R is expressed in J · mol^?1 · K^?1. The given rate expressions are discussed in the framework of earlier kinetic investigations.     

Metalloradicals Supported by a meta‐Carborane Ligand

In this work, a pincer‐type complex [Cp*Ir‐(SNPh)(SNHPh)(C₂B₁₀H₉)] ( 2 ) was synthesized and its reactivity studied in detail. Interestingly, molecular hydrogen can induce the transformation between the metalloradical [Cp*Ir‐(SNPh)₂(C₂B₁₀H₉)] ( 5 ^.) and 2 . A mixed‐valence complex, [(Cp*Ir)₂‐(SNPh)₂(C₂B₁₀H₈)] ( 7 ^.+), was also synthesized by one‐electron oxidation. Studies show that 7 ^.+ is fully delocalized, possessing a four‐centered‐one‐electron (S‐Ir‐Ir‐S) bonding interaction. DFT calculations were also in good agreement with the experimental results.     

负载型BINAP-M类催化剂

1,1'-联萘-2,2'-双二苯膦与金属配位化合物(BINAP-M)作为最重要和著名的手性催化剂之一,过去的几十年中在工业和基础理论研究中受到广泛关注。虽然BINAP-M作为均相手性催化剂具有活性高和选择性好的特点,但存在价格昂贵、应用成本较高和难以回收利用等局限性,特别是催化剂残留在合成产物中,如药品中,限制了其在工业上的大规模应用。因此,寻求既能保持高催化活性,又能方便回收和循环应用的BINAP-M类催化剂成为重要研究课题。本文总结了近年来可回收BINAP-M催化剂研究进展,重点介绍了吸附负载型与共价负载型BINAP-M催化剂在可回收领域的研究成果,分析讨论了不同类型可回收的负载型BINAP-M催化剂的优缺点。在此基础上,本文还介绍了一种具有“柔性桥链”结构的共价负载BINAP-M催化剂,并分析了其在“拟均相”催化反应中的应用前景,为负载型催化剂的设计与制备提供了新的研究思路。     

Synthesis of Diacyl Bisulfides Using a Polymer Supported Reagent

Various diacyl disulfides are prepared easily in high yields from the corresponding acid chlorides under mild and non-aqueous conditions using a polymer supported reagent obtained from elemental sulfur and Amberlyst (OH). The polymeric reagent is regenerable.     

Nitration of Polycyclic Aromatic Hydrocarbons Using a Supported Catalyst

We report the use of catalyst, sulfuric acid supported on silica-gel, as promising method for facile, high yielding, regioselective syntheses of mononitrated polycyclic aromatic hydrocarbons, 6-nitrochrysene, 1-nitropyrene, 1-nitronaphthalene, 2-nitrofluorene, 3-nitrofluoranthene, and 9-nitroanthracene.     

Supported lipid bilayer self-spreading on a nanostructured silicon surface

We report on the self-spreading behavior of a supported lipid bilayer (SLB) on a silicon surface with various 100 nm nanostructures. SLBs have been successfully grown from a small spot of a lipid molecule source both on a flat surface and uneven surfaces with 100 nm up-and-down nanostructures. After an hour, the self-spreading SLB forms a large circle or an ellipse depending on the nanostructure pattern. The results are explained by a model that shows that a single-layer SLB grows along the nanostructured surfaces. The model is further supported by a quantitative analyses of our data. We also discuss the stability of the SLB on nanostructured surfaces in terms of the balance between its bending and adhesion energies.     

Supported lipopolysaccharide bilayers

In this report, the formation of supported lipopolysaccharide bilayers (LPS-SLBs) is studied with extracted native and glycoengineered LPS from Escherichia coli ( E. coli ) and Salmonella enterica sv typhimurium ( S. typhimurium ) to assemble a platform that allows measurement of LPS membrane structure and the detection of membrane tethered saccharide-protein interactions. We present quartz crystal microbalance with dissipation monitoring (QCM-D) and fluorescence recovery after photobleaching (FRAP) characterization of LPS-SLBs with different LPS species, having, for example, different molecular weights, that show successful formation of SLBs through vesicle fusion on SiO(2) surfaces with LPS fractions up to 50 wt %. The thickness of the LPS bilayers were investigated with AFM force-distance measurements which showed only a slight thickness increase compared to pure POPC SLBs. The E. coli LPS were chosen to study the saccharide-protein interaction between the Htype II glycan epitope and the Ralstonia solanacearum lectin (RSL). RSL specifically recognizes fucose sugars, which are present in the used Htype II glycan epitope and absent in the epitopes LPS1 and EY2. We show via fluorescence microscopy that the specific, but weak and multivalent interaction can be detected and discriminated on the LPS-SLB platform.     

Supported carbon molecular sieve membranes based on a phenolic resin

The preparation of a composite carbon membrane for separation of gas mixtures is described. The membrane is formed by a thin microporous carbon layer (thickness, 2 μm) obtained by pyrolysis of a phenolic resin film supported over a macroporous carbon substrate (pore size, 1 μm; porosity, 30%). The microporous carbon layer exhibits molecular sieving properties and it allows the separation of gases depending on their molecular size. The micropore size was estimated to be around 4.2 Å. Single and mixed gas permeation experiments were performed at different temperatures between 25°C and 150°C, and pressures between 1 and 3.5 bar. The carbon membrane shows high selectivities for the separation of permanent gases like O₂/N₂ system (selectivity≈10 at 25°C). Gas mixtures like CO₂/N₂ and CO₂/CH₄ are successfully separated by means of prepared membranes. For example, the membrane prepared by carbonization at 700°C shows at 25°C the following separation factors: CO₂/N₂≈45 and CO₂/CH₄≈160.     

羧甲基纤维素支载三亚乙基四胺催化Knoevenagel反应

烯烃;羧甲基纤维素支载三亚乙基四胺催化Knoevenagel反应