超细Ni-Cu-Co-La的制备及其催化乙腈加氢性能

以水合肼和硼氢化钾为共还原剂制备了四元合金催化剂Ni-Cu-Co-La,并将其应用于乙腈催化加氢反应.采用X射线衍射、X射线光电子能谱、透射电镜和H2程序升温脱附对催化剂进行了表征,考察了催化剂组分对乙腈选择性加氢制乙胺催化性能的影响.结果表明,Cu,Co和La的加入均不同程度地提高了催化剂的活性和选择性,在反应压力1.8 MPa,反应温度120℃,反应时间1 h的条件下,乙腈转化率和乙胺选择性分别为100%和98.24%,优于使用Raney Ni、非晶态Ni-B和Co-B合金催化剂时的结果.     

Structural and electrochemical studies of annealed LiNiVO4 thin films

We prepared stoichiometric lithium nickel vanadate amorphous thin films by using r.f. magnetron sputtering under controlled oxygen partial pressure. The amorphous films were heated at various temperatures, 300–600 °C, for 8 h. The as‐deposited and annealed thin films were characterized by Rutherford backscattering spectroscopy, nuclear reaction analysis, Auger electron spectroscopy, X‐ray diffraction, scanning electron microscopy and atomic force microscopy. The electrochemical behavior of the various films was studied by the galvanostatic method. The cells were tested in a liquid electrolyte at room temperature, with lithium metal used as the counter and reference electrode. The best electrochemical storage value was obtained with the thin film annealed at 300 °C, which showed superior capacity and small capacity loss during cycling. Copyright © 2007 John Wiley & Sons, Ltd.     

溶出伏安法同时测定水中痕量铀和镍

本文报道了同时测定钴和镍的一种方法.在 0.01mol/L NH_3·H_2O-0.01mol/LNH_4Cl-3.0×10~(-5)mol/L安息香缩氨基硫脲(BTSC)溶液中,钴(Ⅱ)和镍(Ⅱ)均产生非常灵敏的还原波,其峰电位分别是:-0.94和-0.75V(vs.SCE),峰电流与钴和镍的浓度分别在2.0×10~(-8)~1.0×10~(-6)和1.0×10~(-8)~8.0×10~(-7)mol/L范围内成直线关系,该方法用于测定水中痕量钴和镍,相对标准偏差分别为1.4~2.0%和2.1~2.5%,回收率分别在98.0%~101.8%和97.9%~102.1%之间.     

Vapor pressure,speciation, and chemical activities in highly concentrated sodium borate solutions at 277 and 317°C

The system H₂O-B₂O₃-Na₂O has been studied experimentally at 277 and 317°C. The activities of water and boric acid have been determined at mole ratios Na/B from 0 to 1.5, and total dissolved solids 3 to 80 weight percent. The activity of boric acid has been fitted to within experimental error using a speciation model with eight complex species. This model is consistent with the model previously published by Mesmer et al. The electrolyte properties of the liquid are modeled using the Pitzer-Simonson model of very concentrated electrolyte solutions. The calculated values of water activity agree with experiment, and the activity of NaOH and pOH have also been calculated. The potassium borate system also was briefly studied at 317°C, and is adequately described by a model with five complex species. The potassium borate liquid is more alkaline at K/B= 1 than a sodium borate liquid at the same mole ratio, but pOH in the two systems is the same at lower mole ratios.     

LiCaBO3的合成和LiBO2-CaO二元体系相图

某些无水硼酸盐具有熔点高、耐潮解、损伤阈值高、光学透过波段好等优点,在材料科学领域中一直受到人们的注视。陈创天等首次得到新型紫外倍频材料—低温相偏硼酸钡。之后,又合成了具有倍频效应的晶体材料α-LiCdBO_3。     

一个二维梯状化合物[Ni(μ1，5-dca)2(en)]n的合成，结构和磁性(英)

A new nickel(Ⅱ)-dicyanamide compound, [Ni(dca)₂(en)]_n (1) (dca=dicyanamide anion, [N(CN)₂]^-); en=ethylene diamine), has been synthesized and its structure has been determined by single crystal X-ray diffraction analysis. The crystal is monoclinic, space group P2₁/n with unit cell dimensions: a=0.694 3(1) nm, b=1.041 5(2) nm, c=1.4132(2) nm, and β=90.381°, Z=4, V=1.011 0(3) nm³. In this compound, the adjacent nickel atoms are connected by dca all in μ_1，5-bridging mode to form ladder-like units, which are linked with double dca bridges to generate a regular infinite stair-like structure. Temperature-dependent magnetic susceptibility was also characterized for this compound. CCDC: 208276.     

Preparation and catalytic performance of superfine Ni/BaTiO3 catalyst

Superfine Ni/BaTiO₃ catalysts were prepared by impregnation method and used successfully for CO₂ reforming CH₄ to syngas. The effects of preparation method and the temperatures of calcination, reduction and reaction on the catalytic activity of the Ni/BaTiO₃ system were investigated. This revised version was published online in June 2006 with corrections to the Cover Date.     

离子液体中用Heck反应合成2-取代萘烯丙醇化合物

利用Heck反应, 在离子液体、金属钯或镍、碱和膦配体反应体系中, 由卤代萘与烯丙醇反应, 制得了高收率和高选择性的2-取代萘烯丙醇化合物. 该方法原料便宜易得、操作简单、反应体系可循环使用. 并讨论了醋酸镍替代醋酸钯、不同膦配体、溶剂及碱对反应转化率的影响. 通过核磁共振、红外光谱、质谱和元素分析对产物的结构进行了表征.     

La[B5O8(OH)(H2O)]NO3•2H2O的合成与结构

采用熔融硼酸法合成了一种具有层状结构的新型水合稀土多硼酸盐, La[B₅O₈(OH)(H₂O)]NO₃•2H₂O, 并利用单晶X射线衍射技术确定了它的结构. 它属于单斜晶系, P21/n空间群. 其基本构建单元 (fundamental building block, 简称FBB)是由三个BO4和两个BO3基团所构成的一个双三元环[B5O12]基团. 结构中每一个FBB通过共顶点氧原子与周围四个同样的单元连接成具有九元环窗口的二维[B5O10]层, La³⁺位于九元环中心附近. [B5O10]层沿着b方向进行堆积, 硝酸根离子和结构中部分结晶水分子位于相邻的[B5O10]层之间.