负载型双核配合物Cu2(μ-iOPr)2/SiO2的制备与表征及其超临界条件下合成DMC的反应性能

采用表面改性和离子交换相结合的方法制备了SiO2负载的Cu2(μ-iOPr)2双核配合物催化剂,用化学分析、IR、TPD-MS和超临界反应技术考察了催化剂的表面构造及CO2和CH3OH在催化剂上的化学吸附和超临界条件下的反应性能.结果表明负载型双核配合物Cu2(μ-iOPr)2/SiO2中金属离子Cu2+与载体SiO2表面O2-以双齿配位键合,配体以桥基形式连接双金属离子形成双核物种Cu2(μ-iOPr)2;CO2在催化剂表面存在桥式和异丙氧碳酸酯基两种吸附态,其中异丙氧碳酸酯基吸附态是生成DMC的关键物种;CH3OH在催化剂上只有一种分子吸附态.在适宜的超临界条件(温度130℃,压力7.5MPa,催化剂/甲醇=0.05(质量比))下,DMC的选择性为100%,甲醇的转化率可达5%左右.     

多孔ZSM-5沸石负载Ni2P催化剂对苯乙炔的选择性加氢性能

以酸性多孔ZSM-5沸石(HZSM-5-M)和高比表面积的氧化硅(SiO2)为载体，采用等体积浸渍法制备了负载Ni2P催化剂(Ni2P/HZSM-5-M和Ni2P/SiO2)，对比研究了它们在苯乙炔选择性加氢反应中的催化性能。采用XRD、N2吸附-脱附、NH3-TPD、H2-TPR、SEM和TEM对载体及其负载的Ni2P催化剂进行了表征。催化剂活性结果为：当反应时间为2 h，苯乙炔在Ni2P/HZSM-5-M催化剂的转化率为98.5%，而在Ni2P/SiO2催化剂上仅为45.6%。说明Ni2P/HZSM-5-M催化剂的加氢活性显著高于Ni2P/SiO2催化剂。这是因为，与Ni2P/SiO2催化剂相比，在Ni2P/HZSM-5-M催化剂上形成了小颗粒的Ni2P活性相。同时，Ni2P/HZSM-5-M催化剂的活性具有良好的重复性。     

5-乙酰氨基-2-甲氧基硝基苯的水合肼还原研究

采用自制催化剂，水合肼为还原剂研究了5-乙酰氨基-2-甲氧基硝基苯的还原反应，反应在液相色谱跟踪下进行。80℃下5-乙酰氨基-2-甲氧基硝基苯的还原转化率迭99％，所需的条件分别为：n(C6H4NHCOCH3(OCH3)NO2)：n(N2H4H2O)=1：1．5、催化剂用量20g／mol 5-乙酰氨基-2-甲氧基硝基苯、反应时间6小时，还原最终产物组成单一，为相应的氨基物。     

负载型WO3/SiO2-Al2O3催化剂用于合成乙酸乙酯反应研究

考察了SiO2、γ-Al2O3和SiO2-Al2O3载体负载氧化钨作为催化剂用于乙酸乙酯合成反应研究,并通过XRD、氮气物理吸附、Raman和NH3-TPD对催化剂进行表征。结果表明,氧化钨负载在SiO2-Al2O3载体上,具有更强的酸性和更高的酸量,有利于促进乙酸乙酯合成反应进行。当W在SiO2-Al2O3载体表面的负载量为8%(质量分数,下同)时,乙酸转化率最高可以达到69.7%,载体表面WO3晶体颗粒不利于提高酯化反应活性。     

咪唑烷-2-亚胺为配体的镍配合物催化的降冰片烯与苯乙烯共聚

为了研究[P, N]型镍催化剂的双重强供电子效应对烯烃与极性单体共聚性能的影响，本文设计合成了两种咪唑烷-2-亚胺为配体的镍配合物Ni1和Ni2,并通过核磁对其表征，研究了该类镍配合物在二氯乙基铝(EtClAl₂)助催化剂的活化下催化降冰片烯均聚及其与苯乙烯的共聚行为。结果表明，以EtClAl₂为助催化剂时，配合物Ni1催化降冰片烯均聚活性高达1.92×10⁷ g/(mol·h)。该体系配合物同样有效催化降冰片烯与苯乙烯共聚，Ni1的聚合活性高达2.14×10⁶ g/(mol·h)。该体系催化剂对降冰片烯与苯乙烯共聚表现出良好的聚合性能，从而为高效镍金属催化剂的开发提供理论依据。     

助剂对Ni/SiO2催化剂1,4-丁炔二醇加氢性能的影响

通过分步浸渍法在Ni/SiO 2催化剂中分别引入Zn、Cu、La、Mo、Co金属助剂,结合N 2物理吸附-脱附、XRD、H 2-TPR和NH 3-TPD等表征手段研究金属助剂对1,4-丁炔二醇加氢性能的影响。结果发现,Mo的引入使Ni/SiO 2催化剂的初始活性大幅增加,但反应2 h后活性下降,归因于催化剂表面酸中心使催化剂积炭失活;引入Cu、La及Co后的催化剂活性较低,推测是由于催化剂表面产生强吸附氢物种,不利于1,4-丁炔二醇加氢反应进行;与其他样品相比,Zn的引入使催化剂保持了Ni/SiO 2催化剂高的1,4-丁炔二醇加氢活性,同时可有效降低产物中2-羟基四氢呋喃副产物含量,提高目标产物1,4-丁二醇收率。     

用于烯烃均聚和共聚的新型催化剂 VO(P204)2/Et3Al2Cl3

研究了VO(P204)2配合物与Et3Al2Cl3,组成的催化剂作用下的乙烯均聚和乙烯／丙烯共聚。VO(P204)2催化剂聚合乙烯的活性及其活性中心的寿命均高于VOCl3催化剂,并具有良好的氢调敏感性,既可使乙烯、丙烯进行无规共聚,又可使乙烯、丙烯和乙叉降冰片烯进行三元共聚。     

Ni2P/TiO2的制备、表征及其加氢脱硫反应性能

利用程序升温还原方法合成了Ni2P／TiO2催化剂,采用H2-TPR、XRD、XPS等技术对样品的结构和性质进行了表征,研究了催化剂对噻吩的常压加氢脱硫反应性能。结果表明,在TiO2为载体的负载型催化剂上,Ni2P为主要活性相,无明显的单质Ni相;与Ni2P／SiO2相比,Ni2P／TiO2催化剂对噻吩常压加氢脱硫反应有较高的转化率以及良好的稳定性,噻吩稳定转化率达到了36％左右。     

气相常压法α-蒎烯加氢制蒎烷Ni/γ-Al2O3催化剂研究

对Ni／γ-Al2O3催化剂在气相常压法α-蒎烯加氢反应中的作用进行了研究,TPR结果显示NiO与γ-Al2O3发生了相互作用,进入了γ-Al2O3表面上的四面体和八面体空位,其中由进入γ-Al2O3表面上八面体空位的NiO还原出的金属Ni是本反应的催化剂成分,而进入四面体的Ni不起作用。增加Ni含量利于提高α-蒎烯的转化率。     

负载型TiO2催化苯酚和草酸二甲酯酯交换反应

使用负载型TiO2/SiO2催化苯酚和草酸二甲酯酯交换反应合成草酸二苯酯.通过对TiO2/SiO2催化剂进行XRD、BET化学吸附、NH3-TPD、XPS等表征以及活性测试,结果表明在苯酚和草酸二甲酯酯交换反应中,负载型TiO2的催化性能与TiO2在载体表面的分散状态和催化剂的弱酸性密切相关.微晶态TiO2的产生会导致催化性能的下降.确定了较佳的焙烧温度为550℃,以该温度焙烧的TiO2/SiO2为催化剂,TiO2负载量为13%时,草酸二甲酯的转化率、甲基苯基草酸酯与草酸二苯酯的收率分别为53.1%、38.3%、14.5%.初步探讨了该反应条件下催化剂的失活.     

ZrB2质与TiB2质耐火材料

介绍了ZrB2 与TiB2 以及其他一些非氧化物高温材料的性质 ;ZrB2 与TiB2 在高温工业中的应用与预期发展 ;ZrB2 与TiB2 原料与制品的生产 ,包括自蔓延高温合成ZrB2 与TiB2 ;ZrB2 质与TiB2 质复合材料 ,如ZrB2 -SiC ,TiB2-SiC ,ZrB2 -BN ,TiB2 -BN ,ZrB2 -MoSi2 ,TiB2 -MoSi2 ,ZrB2-C ,TiB2 -C ,ZrB2 -B4C ,TiB2 -B4C等。     

Electronic Structure and Properties of the O2+2, SO2+ and S2+2 Diatomic Dications

Multiply charged ions show novel energetic features which can potentially have useful photophysical properties. In order to investigate these interesting type systems, energy interaction curves for the ground and excited electronic states of O²⁺₂, SO²⁺, and S²⁺₂ have been generated by the ab initio complete active space multiconfiguration self-consistent field (CAS-MCSCF) method. The calculations were carried out in a triple-zeta sp plus double-zeta d Gaussian function basis set using compact effective potentials to replace the core electrons. In order to gauge the accuracy of the results, analogous calculations were carried out on the valence isoelectronic N₂ and NO⁺ systems for which experimental information is available for comparison of geometric and spectroscopic properties. Diverse high energy spectroscopy experiments on O²⁺₂ are interpreted and reconciled using the calculated ground and excited state energy interaction curves. Special attention is paid to the ₃Σ₊^u state, whose location and character have been particularly puzzling. Almost all the dication molecular states studied show the characteristic avoided crossing of diabatic states which gives a trapped equilibrium structure and a barrier to dissociation. These features make the dication kinetically stable, but thermodynamically unstable with an exothermic dissociation energy. The spectroscopy experiments on O²⁺₂ show that these states are experimentally attainable.     

Eu~(2+)掺杂SrSi_2O_2N_2和Sr_(0.37)Ba_(0.60)Si_2O_2N_2荧光粉的发光性能及应用

采用高温固相法合成Sr_(0.97)Eu_(0.03)Si_2O_2N_2和Sr_(0.37)Ba_(0.60)Eu_(0.03)Si_2O_2N_2荧光粉,通过X射线衍射、激发光谱、发射光谱及转换后LED器件的性能等研究了荧光粉的结构、发光性能和稳定性。结果表明:在稀土Eu2+掺杂的Sr Si2O2N2荧光粉中,当部分Sr2+被Ba2+取代后,形成三斜晶系的Sr_(0.37)Ba_(0.60)Eu_(0.03)Si_2O_2N_2荧光粉,激发和发射光谱红移,在近紫外-蓝光区具有更高的激发效率。将2种荧光粉与Ga(N)In芯片封装,Sr0.37Ba0.60Eu0.03Si2O2N2荧光粉转换的白光LED器件,在光效、显色指数和光效维持特性方面均高于Sr_(0.97)Eu_(0.03)Si_2O_2N_2转换的LED器件。     

沉淀法白炭黑与纳米级二氧化硅

依据二氧化硅粒子的形成过程，指出传统沉淀法白炭黑并不具有科学意义上的纳米实质，研究重点侧重于改进其分散性能，同时也简介了纳米二氧化硅的制备方法及用途。     

多卤代吡啶选择性合成醚类的反应

以KOH为碱,DMSO为溶剂,在空气中,温度为50℃的条件下,多卤代吡啶和苯酚类化合物反应,形成相应的醚类化合物,该反应具有很好的收率以及区域选择性,是一种有效构建C-O键的方法;以K_2CO_3为碱,DMSO和H_2O为溶剂,在空气中,室温下,多卤代吡啶和苯硫酚类化合物反应,形成相应的的吡啶硫醚化合物,该反应也具有很好的收率以及区域选择性,是一种有效构建C-S键的方法。     

Separation and purification of aflatoxins B1, B2, G1 and G2, and comparison of semi-synthetic aflatoxins B2 and G2 with naturally-occurring aflatoxins B2 and G2

A method is described for the isolation of highly purified aflatoxins B₁, B₂, G₁ and G₂ from extracts ofAspergillus flavus. The four aflatoxins, isolated from background impurities by rapid passage of the extracts through an acid alumina column, are separated from each other by chromatography on a silica gel column. Aflatoxins B₂ and G₂ are prepared by hydrogenation of the mixture of aflatoxins B₁, B₂, G₁ and G₂ and then separated by elution from a silica gel column with chloroform containing 0.7% ethanol. A comparison of semi-synthetic aflatoxins B₂ and G₂ with naturally-occurring aflatoxins B₂ and G₂ shows no significant difference in physical properties. Presented at the AOCS-AACC Meeting, Washington, D.C. April, 1968.     

氢氧直接合成法制过氧化氢技术进展

氢气和氧气直接合成过氧化氢是典型的原子经济性反应，因过程简单、产品清洁、生产成本低而成为催化领域研究开发的一个热点。总结了该法近年来在催化剂活性组分的选取及载体方面的进展；详细介绍了溶剂的选取和反应机理；讨论了各种反应器的安全性。指出今后的研究重点是提高氢气利用率、开发新型的反应器、提高过程的安全性。     

Solubility and microstructural development of TiO2-containing 3Al2O3·2SiO2 and 2Al2O3·SiO2 mullites obtained from single-phase gels

The interdependence of the titanium oxide amount and the anisotropic growth of mullites prepared from single-phase gels were investigated. Gels with stoichiometries 3(Al_2−xTi_xO₃)·2(SiO₂) and 2(Al_2−xTi_xO₃)·(SiO₂), with 0 ≤ x ≤ 0.15 were prepared by the semialkoxide method. Gels and specimens heated at temperatures between 1200 and 1600 °C were characterized by using infrared spectroscopy (IR), X-ray diffraction (XRD) and transmission and field emission scanning electron microscopies (TEM and FESEM). Al₂TiO₅ as minor impurity was detected in both series of mullites for gel precursor compositions x = 0.10 and x = 0.15, obtained at temperatures between 1200 and 1600 °C. Variations of lattice parameters of mullite, processed at temperatures from the range between 1400 and 1600 °C, with the starting nominal amount of titanium oxide indicated that the solubility limit of titanium oxide was in ranges 3.8–4.1 and 4.1–4.4 wt% TiO₂ for 3:2 and 2:1 mullites series, respectively. The anisotropic growth of titanium-doped mullite crystalline grains was significant only when the nominal amount of titanium oxide exceeded the limit of solubility into the mullite structure (for both mullite series). Stronger anisotropy occurred for the 3:2 series specimens, i.e. for the SiO₂-richer mullites. In both series of mullites, the anisotropic grain growth was observed for the process temperatures higher than 1400 °C; the crystalline grains of mullites processed at lower temperatures were equiaxials and of almost the same size.     

生产乙炔对电石的要求及乙炔清净

目前国内外乙炔大部分仍是由电石制得。然而由于工业电石除CaC2 外还含有很多杂质 ,所以生产乙炔不仅要求电石的纯度、粒度 ,还要求水温。一般电石的块度采用 8～ 2 5mm ,发生器温度控制在 85± 5℃ ,乙炔气体中含H2 S、H3 P、NH3 等气体会使氯乙烯合成氯化催化剂活性下降。因此 ,必须对乙炔气体进行清洁。采用次氯酸钠液体的氧化性将乙炔中的杂质氧化成酸性物质而除去。