Ni-M/SiO2催化1,4-丁炔二醇加氢的金属助剂效应

以SiO₂气凝胶为载体,采用等体积浸渍法制备了Ni/SiO₂及不同金属助剂改性的Ni-M/SiO₂（M=Fe、Co、Cu）催化剂,利用ICP、BET、XRD、H₂-TPR、H₂-TPD等手段对催化剂进行了表征,考察了不同第二金属对催化剂结构与1,4-丁炔二醇加氢性能的影响.结果表明,第二金属与Ni物种具有不同程度的双金属协同效应,其中Cu的加入不仅能够提高Ni活性物种的分散度,而且Ni-Cu双金属间的相互作用改善了NiO物种的还原性能及氢活化能力,有利于氢和1,4-丁炔二醇在活性位点的快速转化.在反应温度50℃,氢压1 MPa,反应时间3 h的加氢评价条件下,15Ni5Cu/SiO₂催化剂不仅可以实现1,4-丁炔二醇的完全转化,而且能够有效降低难分离副产物2-羟基四氢呋喃的含量,具有最优的加氢活性和对1,4-丁烯二醇的选择性.     

有机改性对粘土负载镍催化剂的促进作用及其萘加氢性能

以有机改性后的十六烷基三甲基溴化铵柱撑蒙脱石（CTAB-MMT）为载体,采用浸渍法制备了Ni/MMT催化剂. 通过傅里叶红外光谱、X射线衍射、H₂程序升温脱附、N₂物理吸附以及紫外漫散射等物理化学手段对催化剂进行了表征;并结合微型高压反应釜萘加氢反应,评价了催化剂的加氢性能. 结果表明,有机改性显著改善了Ni/MMT催化剂的金属Ni分散度和织构性质,且所制催化剂表现出优异的萘加氢性能,Ni萘转化率达到88.2%,不仅远高于未处理催化剂（13.1%）和Al₂O₃柱撑处理催化剂（24.2%）,而且高于Ni/SBA-15催化剂（68.2%）. 鉴于CTAB有机柱撑体在催化剂还原过程因热解而消除,其对催化剂所起的作用主要发生于浸渍过程,提出了有机改性在浸渍过程对Ni/MMT催化剂的促进作用机制.     

含双金属的DUSY负载磷钨酸催化剂上正庚烷 临氢异构化

用脱铝USY沸石(DUSY)负载12-磷钨酸(PW), 并以此为载体制备含Pt和Ce(或La)的双金属催化剂, 用XRD, BET, IR以及氢吸附等表征了催化剂的物化性质, 并在常压固定床反应器上考察催化剂的正庚烷临氢异构化反应性能. 结果表明, USY经过水蒸气和酸的联合处理并负载了PW和双金属以后仍能保持沸石原有结构, 同时催化剂中的PW保持了完好的Keggin结构, 金属助剂Ce的加入可以明显提高贵金属Pt的分散度; 在含Pt的催化剂中掺杂Ce或La, 特别是Ce后, 可显著提高催化剂的低温活性和异构化产物选择性. 催化剂的优化组成为 15CePt-PW/DUSY, 采用这一催化剂, 正庚烷异构化的优化反应条件为: 反应温度250℃, 液时空速1.4 h^-1, 在此条件下正庚烷的转化率为70.3%,异构化产物的选择性可达94.1%.     

Ni/MWCNT及镧改性Ni/MWCNT催化CO2甲烷化反应的性能

以多壁碳纳米管(MWCNT)为载体, 通过浸渍法制备了负载型镍催化剂和稀土镧改性的镍催化剂, 并对其二氧化碳甲烷化的催化性能进行了研究. 借助比表面积测试、程序升温还原(TPR)、X射线衍射(XRD)和X射线光电子能谱(XPS)等表征手段研究了稀土镧的添加对Ni/MWCNT催化剂结构和表面组成、催化剂还原性能以及CO₂甲烷化反应性能的影响. 结果表明: 稀土镧改性的Ni/MWCNT较Ni/MWCNT催化剂具有更好的CO₂甲烷化活性, 镧组分的加入提高了催化剂表面的镍物种浓度和分散度, 弱化了氧化镍与载体MWCNT之间的相互作用, 促进了氧化镍的还原, 同时提高了表面镍物种的电子密度, 增加了对反应物的吸附能力, 从而提高了其CO₂甲烷化活性. 制备过程中稀土镧的添加次序对催化性能有较明显的影响, 其活性顺序为先浸渍镧后浸渍镍制备的催化剂活性明显好于先浸渍镍后浸渍镧制备的催化剂.     

Ni-Mo氮化物催化剂:合成及其丙烷氨氧化催化性能简

分别采用溶胶-凝胶法、旋转蒸发微波干燥法、共沉淀法、浸渍法和机械混合法制备Ni-Mo氧化物前驱体. 以H₂和N₂的混合气为氮化气体,采用程序升温氮化法合成了镍钼氮化物催化剂. 利用X射线衍射、总氮含量分析、X射线光电子能谱及H₂程序升温还原对Ni-Mo氧化物前体及氮化物催化剂进行了表征. 将上述Ni-Mo氮化物催化剂用于丙烷氨氧化反应中. 结果表明,Ni-Mo氧化物前驱体的制备方法影响其氮化物催化剂上丙烷氨氧化反应性能. Ni-Mo氮化物催化剂中氮物种的移动性及反应性对产物丙烯腈选择性的影响较大,共沉淀法制备的催化剂存在大量的活性氮物种,因而具有良好的催化丙烷氨氧化反应活性.     

钾调变Mo/SBA-15催化剂用于乙烷选择氧化制乙醛

采用两步浸渍法制备钾改性的Mo/SBA-15 催化剂. 采用N₂吸附,X射线衍射（XRD）,透射电镜（TEM）,紫外-可见（UV-Vis）吸收光谱,拉曼（Raman）光谱,NH₃程序升温脱附（NH₃-TPD）,CO₂程序升温脱附（CO₂-TPD）,H₂程序升温还原（H₂-TPR）等手段表征催化剂的物理化学性质. 研究结果表明,在Mo_0.75/SBA-15 中添加K之后,有新物种钾钼酸盐生成,并且当K/Mo的摩尔比不同时,钼物种的存在状态也不同. 添加钾之后,催化剂的活性和总醛（甲醛、乙醛、丙烯醛）的选择性均有所提高,并且受钾的添加量影响. 在575 ℃时,在K_0.25-Mo_0.75/SBA-15催化剂上醛的收率可高达8.5%（摩尔分数）.     

Cu对Ni-Cu/SiO2催化1,4-丁炔二醇加氢性能的影响

采用超临界干燥法和等体积浸渍法制备了不同Ni/Cu比例的Ni-Cu/SiO₂双金属催化剂,利用ICP、BET、XRD、H₂-TPR、H₂-TPD、NH₃-TPD等手段对催化剂进行了结构表征,考察了不同Ni/Cu比例对催化剂结构以及1,4-丁炔二醇加氢性能的影响.结果表明,少量Cu的引入不仅能够提高Ni活性物种的分散性,而且Ni-Cu双金属间的相互作用改善了NiO物种的还原性能及氢活化能力,有利于氢和1,4-丁炔二醇在活性位点的快速转化.在反应温度50℃,氢压1 MPa,反应时间3 h的加氢评价条件下,Ni/Cu比为3：1时,15Ni5Cu/SiO₂催化材料不仅可以实现BYD的完全转化,而且能够有效降低难分离副产物2-羟基四氢呋喃的含量,具有最优的加氢活性和对1,4-丁烯二醇及1,4-丁二醇的选择性.     

Ni-M(M=Cu，Zn，Ce)/C双金属催化剂上的乙醇气相羰化

利用等体积浸渍法制备了NiM_0.2(M=Cu, Zn, Ce)/C双金属催化剂及Ni/C催化剂,考察了其乙醇气相羰化制丙酸的活性。结果表明,4种催化剂的活性大小顺序为NiCe_0.2/C＞Ni/C＞NiCu_0.2/C＞NiZn_0.2/C,催化剂NiCe_0.2/C的羰化活性最高,乙醇转化率和丙酸的选择性分别为98.0%和95.1%,而催化剂NiZn_0.2/C的羰化活性最低,乙醇转     

金属含量对Ni-Pd/H-Y上正癸烷加氢异构化反应活性和产物选择性的影响

在Y分子筛上浸渍0.1 wt% Pd和0.1–0.5 wt% Ni,用X射线衍射表征了该催化剂的结晶度,用透射电镜测得平均金属粒径.催化剂中Pd和Ni的化学态用X射线光电子能谱测定,其酸性则用氨-程序升温脱附进行了表征,发现一些酸位被Ni2+离子交换.采用程序升温还原表征了HY分子筛负载的Pd, Ni和Pd-Ni催化剂的还原性能.正癸烷加氢异构化反应在200–450 oC和1 atm条件下进行.结果发现,当0.1 wt% Pd/HY中Ni添加量增至0.3 wt%时,正癸烷转化率和异构化选择性增加.单支链和双支链异构体选择性的增加表明该反应遵循质子化环丙烷中间体机理. Ni添加量超过阈值导致活性和异构化选择性急剧下降.综上可见,双金属催化剂更有利于选择性生成双支链异构体,其辛烷值更高.     

溶剂化金属原子浸渍法制备的Ni-Ag/γ-Al2O3催化剂的催化性质研究

应用溶剂化金属原子浸渍(SMAI)法和普通浸渍(CI)法制备了金属含量相同的γ-Al₂O₃负载Ni-Ag双金属催化剂。研究了这些催化剂在甲苯和二丙酮醇加氢以及CO₂甲醇化反应中的催化性质，结果表明与组成相同的普通浸渍法催化剂相比，在所有这些反应中SMAI催化剂都显示出较高的催化活性，这是因为SMAI催化剂具有较高的分散度和还原度(零价金属百分比)。     

Gangliosides from the starfishEvasterias echinosoma: identification of a disialoganglioside containing 8-O-methyl-N-acetylneuraminic acid andN-formylgalactosamine

Gangliosides were isolated from the starfishEvasterias echinosoma and their structures were elucidated by chemical and physicochemical methods. Two major gangliosides were found to be disialogangliosides, whose carbohydrate chain is based on the trisaccharide β-N-acylgalactosaminyl-(l→3)-β-galactosyl-(l→4)-β-glucose (acyl is formyl or acetyl), both residue at of 8-O-methyl-N-acetylneuraminic acid being attached to theN-acylgalactosamine residue at positions 3 and 6. The minor components are disialogangliosides with linear carbohydrate chains in which the terminal sialic acid residue is attached to the penultimateN-acetylneuraminic acid residue at positions 4, 8, or 9. The lipid part of the gangliosides consists of sphingenine and unsubstituted fatty acids (mainly, palmitic and stearic acids). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 156–161, January, 2000.     

Ab initio study of atropisomers of derivatives of 1,8-di-pyridine 9H-fluorene, dibenzo[b,d]furan, 9H-carbazole and dibenzo[b,d]thiophene

Ab initio calculation at HF/6-31G^* and MP2/6-31G^* levels of theory for geometry optimization of some syn- and anti-1,8-di-pyridine 9H-fluorene, dibenzo[b,d]furan, 9H-carbazole and Dibenzo[b,d]thiophene are reported. The rotational barrier energy, heat of formation and Gibbs energy are determined for the conversion of the anti-(syn) to the syn (anti)-isomers at 25 °C in the gas phase. The models are chosen as isomers of 9H-fluorene, dibenzo[b,d]furan, 9H-carbazole and dibenzo[b,d]thiophene as scaffold with pyridine as module. Results obtained show that (at equilibrium) for most of atropisomers the syn- is favored over the anti-isomer. Moreover, the ground state structures show that the modules are not parallel to each other but are tilted away in order to increase separation and there by minimize electrostatic repulsion. In atropisomers of 9H-carbazole the isomers are showing an attraction due to the presence of nitrogen atom. Influence of the position of nitrogen atom on the magnitude of the rotational barriers in these atropisomers is also studied.     

Inclusion compounds of cystostatic active (C5H5)2VCl2 and (CH3C5H4)2VCl2 with α-, β- and γ-cyclodextrines: Synthesis, EPR study and microbiological behavior toward Escherichia coli

The inclusion of vanadocene dichloride (VDC) and 1,1′-dimethyl vanadocene dichloride (MeVDC) into cyclodextrines (α-CD, β-CD and γ-CD) was studied by EPR spectroscopy. It was found that VDC and MeVDC with β-CD and γ-CD form true inclusion compounds, but with α-CD, VDC and MeVDC gave only fine dispersion mixtures. The inclusion was validated by anisotropic EPR spectra of solid samples. In addition, the antimicrobial was validated by anisotropic EPR spectra of solid samples. In addition, the antimicrobial behavior (against E. coli) of each of the complexes was determined. It was established that not only did VDC and MeVDC cause elongation of E. coli, but also the new vanadocene inclusion complexes were effective in this regard.     

The effect of the components of the PdCl2/Fe/I2/Py catalytic system on nitrobenzene carbonylation to ethyl N-phenylcarbamate

The PdCl₂/Fe/I₂/Py catalytic system (Py-pyridine), reported to be highly active in the reaction of nitrobenzene carbonylation to ethyl phenylcarbamate was studied. The present paper describes the role of catalyst components and its effect on the activity and selectivity of the catalyst. The increase in the amount of PdCl₂ in the system while retaining a constant level of the other catalyst components, results in the increase of both carbamate and aniline yields. The increase in the amount of iron while retaining the other components constant, initially causes an increase in the carbamate yield; however, at Fe: Pd ratios higher than 36, the carbamate yield remains constant. The change in the amount of iron has no effect on the amount of aniline formed in the system. An increase in the amount of iodine in the system while retaining the other components constant, results in a decrease in carbamate yield and a considerable increase in the aniline yield of the reaction products.     

正十二烷基-L-羟基脯氨酸手性配位萃取拆分外消旋苯丙氨酸

本文合成新手性配体正十二烷基-L-羟基脯氨酸,研究手性配体正十二烷基-L-羟基脯氨酸与Cu髤配位萃取拆分苯丙氨酸的性能和机理,考察起始氨基酸浓度、配位铜离子浓度、萃取剂浓度、溶液pH值及温度等因素分别对D-和L-苯丙氨酸萃取性能的影响,萃取剂对D-苯丙氨酸的识别能力强。利用多种手段对萃合物的组成进行表征,推测萃合物的结构为1∶1∶1型三元配合物。对比发现:该萃取剂配位萃取拆分苯丙氨酸性能优于正辛基-L-羟基脯氨酸,空间位阻效应反而对拆分有利。     

LaMg_2Cu_(1-x)Ni_x(x=0～0.90)合金的相结构及储氢性能

利用真空感应熔炼技术制备了LaMg2Cu1-xNix(x=0,0.10,0.25,0.50,0.75,0.90)合金,并在0.06MPa氩气保护下于723K退火6h得到测试所用合金铸锭。XRD表明合金LaMg2Cu1-xNix含有ThCr2Si2型的LaMg2Cu2相和CeMg3型的LaMg3相以及少量未知相,随着x的增加,LaMg2Cu2相的晶胞体积先增加后减小,而LaMg3相的晶胞体积几乎不变。通过SEM观察,发现Ni可以有效的减小合金在吸放氢过程中的粉化。当x0.50时,Ni对合金的吸氢速率降低;而当x≥0.50时,Ni的加入可以极大的提高合金的吸氢速率,合金在50s左右就能达到最大吸氢量的90%。当x=0.50时,合金具有较好的综合储氢性能,合金在473K下吸氢量为3.741wt%,49s就可达到最大吸氢量的90%以上。     

Phasengleichgewichte und Stoffwerte im System 1,2-Dichlorethan/n-Propanol/Wasser

Liquid-liquid equilibria of the ternary system 1,2-dichloroethane/n-propanol/water were measured at 20, 30, and 40 °C. In the plot of the system for 20 °C are shown the results of titration (i. e. addition of increasing quantities of water resp. 1,2-dichloroethane to the homogenous mixture of the other components). These results geree well with the plot of extraction results.The binary homogeneous systemsn-propanol/water andn-propanol/1,2-dichloroethane exhibit an non-ideal behaviour. Vapor-liquid equil. of these systems were measures at 133.32 and 666.6 mbar (100 and 500 Torr). The azeotropic points at these pressures are in good agreement with the literature.In addition to this, measurements of the values of surface-tension, viscosity and refractive index were performed.Aqueous solutions ofn-propanol can be determined by the micromethod ofR. Fischer.

Unserem Lehrer, Herrn Universitätsprofessor Dr. et Mr.Robert Fischer zum 75. Geburtstag in Dankbarkeit und Verehrung gewidmet.Die Programme wurden auf der Rechenanlage UNIVAC 494 des Forschungszentrums Graz erstellt.     

金属离子导向自组装的磺酰化对氨基苯甲酸配合物的合成与表征

用普通溶液法合成了4个配合物：[Cu（Ts-p-aba）₂（phen）（H₂O）]_n（1）、[Zn（Ts-p-aba）₂（phen）（H₂O）]·H₂O（2）、[Pb（Ts-p-aba）₂（phen）]2（3）和{[Pb（Ts-p-aba）（phen）（NO₃）]（DMF）}_n（4）（Ts-p-aba=N-对甲苯磺酰对氨基苯甲酸,phen=菲咯啉,DMF=N,N-二甲基甲酰胺）。X-射线单晶衍射结果表明：配合物1和2均为三斜晶系,P1空间群。配合物1的中心铜离子处于变形的八面体配位环境,并通过配体N-对甲苯磺酰对氨基苯甲酸扩展为一维直线链结构;配合物2是个单核分子,锌离子的配位多面体为四角锥体。配合物3和4均为单斜晶系,P2₁/c空间群。配合物3由配体N-对甲苯磺酰对氨基苯甲酸桥联成二聚体,铅离子处于变形的八面体配位环境;配合物4是具有一维链状结构的配位聚合物,铅离子处于变形的一面心八面体配位环境。另外,对4个配合物的热稳定性、电化学性能和荧光性质也进行了研究。     

金属离子导向自组装的磺酰化对氨基苯甲酸配合物的合成与表征

用普通溶液法合成了4个配合物:[Cu(Ts-p-aba)2(phen)(H2O)]n(1)、[Zn(Ts-p-aba)2(phen)(H2O)]·H2O(2)、[Pb(Ts-p-aba)2(phen)]2(3)和{[Pb(Ts-p-aba)(phen)(NO3)](DMF)}n(4)(Ts-p-aba=N-对甲苯磺酰对氨基苯甲酸,phen=菲咯啉,DMF=N,N-二甲基甲酰胺)。X-射线单晶衍射结果表明:配合物1和2均为三斜晶系,P1空间群。配合物1的中心铜离子处于变形的八面体配位环境,并通过配体N-对甲苯磺酰对氨基苯甲酸扩展为一维直线链结构;配合物2是个单核分子,锌离子的配位多面体为四角锥体。配合物3和4均为单斜晶系,P21/c空间群。配合物3由配体N-对甲苯磺酰对氨基苯甲酸桥联成二聚体,铅离子处于变形的八面体配位环境;配合物4是具有一维链状结构的配位聚合物,铅离子处于变形的一面心八面体配位环境。另外,对4个配合物的热稳定性、电化学性能和荧光性质也进行了研究。     

B-frame supported bimetallics. [(PMe2ph)2PtB9H11Ru(η-PrC6H4Me)] and [(PMe2ph)2PtB9H9Ru(η-PrC6H4Me)]; an interesting pair of electron-deficient nido and closo geometries

[7,7-(PMe₂Ph)₂-9-(η⁶-^isoPrC₆H₄Me)-7,9-PtRuB₉H₁₁] has a formal closo Wadian cluster-electron count, but a nido geometry, whereas [1-(η⁶-^isoPrC₆H₄Me)-4,4-(PMe₂Ph)₂-1-4-RuPtB₉H₉], which does have a closo geometry, has a formal sub-closo cluster electron count; both compounds are formed in the reaction between [6-(η⁶-^isoPrC₆H₄Me)-nido-6 RuB₉H₁₃], KH and [PtCl₂(PMe₂Ph)₂].