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901.
S. Manivannan R. Prabhakaran K. P. Balasubramanian V. Dhanabal R. Karvembu V. Chinnusamy K. Natarajan 《应用有机金属化学》2007,21(11):952-957
The synthesis and characterization of several hexa‐coordinated ruthenium(III) Schiff base complexes of the type [RuX(EPh3)(L)] (X = Cl or Br; E = P or As; L = dianion of the tetradentate Schiff base) are reported. IR, EPR, electronic spectra and cyclic voltammetric data of the complexes are discussed. An octahedral geometry has been tentatively proposed for all of these complexes. The new complexes have been subjected to catalytic activity in the reaction of oxidation of alcohols in the presence of N‐methylmorpholine‐N‐oxide. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
902.
Porous perovskite-type complex oxides LaCoO3 and La0·95Sr0·05Ni0·05Co0·95O3 were produced by combustion method. The properties of these porous materials such as crystal structures, particle sizes,
surface patterns, pore size, surface area and pore volume were characterized by X-ray diffraction( XRD), scanning electron
microscopy(SEM) and BET measurements. The results indicated that all porous materials are of the perovskite-type complex oxides.
Doping Sr2+ ions on site A and doping Ni2+ ions on site B entered the crystal lattices of LaCoO3 in the place of La3+ and Co3+, respectively, and the maximum peak of XRD patterns of doping sample was weaken and broaden. Morphological microscopy demonstrated
agglomerates involved mostly thin smooth flakes and layers perforated by a large number of pores and its lamella decreased
with the introduction of Sr2+ and Ni2+. Hysteresis loop in the N2 adsorption-desorption isotherm of samples indicated its porous structures and the doping effect on its pore size, surface
area and pore volume were improved. The porous catalysts have been tested for methane catalytic combustion and the results
showed that these catalysts possessed high catalytic activity. 相似文献
903.
SO2 是危害最为严重的大气污染物之一 ,也是造成酸雨的元凶。将SO2 选择性还原为单质硫 ,既能消除SO2 对环境的污染 ,又能回收单质硫 ,具有特别重要的意义。根据所用的还原剂的不同 ,催化还原SO2 到单质硫可分为H2 、炭、烃类 (主要是CH4 )、CO和NH3还原法[1] 。氨还原法是基于氨的催化分解生成N2 和H2 混合气 ,其中的H2 再还原SO2 到硫和H2 S ,然后进行高温Claus反应生成单质硫。Paik[2 ] 等以第四周期过渡金属硫化物载于Al2 O3 作为催化剂 ,研究了H2 还原SO2 为单质硫的反应 ,认为过渡金属硫化物是… 相似文献
904.
在制备单氨基取代卟啉铁Fe(ATPP)Cl的基础上,以具有良好成膜特性的丙烯腈/丙烯酸共聚物为载体,通过氨基与羧基的缩合,得到新型的高聚物负载卟啉铁(Poly-Fe(ATPP)Cl).以分子氧-抗坏血酸-Poly-Fe(ATPP)Cl作为细胞色素P-450的氧化模拟体系,研究了其对环己烷在常温常压下温和氧化的催化性能,并考察反应时间、还原剂用量、轴向配体以及催化剂的回收利用等因素的影响. 相似文献
905.
Huaming Li Wenshuai Zhu Xiaoying He Qi Zhang Jianming Pan Yongsheng Yan 《Reaction Kinetics and Catalysis Letters》2007,92(2):319-327
An amphiphilic oxodiperoxo complex of tungsten using 8-quinolinol (QOH) as ligand has been synthesized and characterized by
elemental analyses, gravimetry, chemistry titration, TG/DSC, IR and UV-vis spectroscopy. Oxidation of cyclohexene, cyclohexanol,
cyclohexanone, cyclohexene oxide and 1,2-cyclohexane-diol to adipic acid in one-step was conducted by this complex catalyst
using 30 wt.% hydrogen peroxide in the absence of organic solvent and phase-transfer catalyst. The effect of the reaction
conditions on the oxidation of cyclohexene was studied by varying the amount of the catalyst, reaction temperature, reaction
time and the amount of hydrogen peroxide. The results showed that oxodiperoxo tungsten complex with QOH as ligand could achieve
89.8% yield of adipic acid at 90°C by refluxing for 20 h. 相似文献
906.
P. Palade G. Principi S. Sartori A. Maddalena S. Lo Russo G. Schinteie V. Kuncser G. Filoti 《Hyperfine Interactions》2006,168(1-3):1029-1035
Mg–Ni–Fe magnesium-rich intermetallic compounds were prepared following two distinct routes. A Mg88Ni11Fe1 sample (A) was prepared by melt spinning Mg–Ni–Fe pellets and then by high-energy ball milling for 6 h the obtained ribbons. A (MgH2)88Ni11Fe1 sample (B) was obtained by high-energy ball milling for 20 h a mixture of Ni, Fe and MgH2 powders in the due proportions. A SPEX8000 shaker mill with a 10:1 ball to powder ratio was used for milling in argon atmosphere. The samples were submitted to repeated hydrogen absorption/desorption cycles in a Sievert type gas–solid reaction controller at temperatures in the range 520?÷?590 K and a maximum pressure of 2.5 MPa during absorption. The samples were analysed before and after the hydrogen absorption/desorption cycles by X-ray diffraction and Mössbauer spectroscopy. The results concerning the hydrogen storage properties of the studied compounds are discussed in connection with the micro-structural characteristics found by means of the used analytical techniques. The improved kinetics of hydrogen desorption for sample A, in comparison to sample B, has been ascribed to the different behaviour of iron atoms in the two cases, as proved by Mössbauer spectroscopy. In fact, iron results homogeneously distributed in sample A, partly at the Mg2Ni grain boundaries, with catalytic effect on the gas–solid reaction; in sample B, instead, iron is dispersed inside the hydride powder as metallic iron or superparamagnetic iron. 相似文献
907.
2,4-Bis(3,5-dimethylpyrazol-1-yl)-6-methoxyl-1,3,5-triazine(bpt) has been synthesized by using a new, simple and general method with high yields. Reactions of bpt with Ni(CIO4)2 · 6H2O and Zn(CIO4)2 · 6H2O in methanol gave mononuclear complex [Ni(bpt)2] · (CIO4)2 · H2O and ternary complex [Zn(mpt)2(dmp)](CIO4)2 respectively, where mpt (2,4-dimethoxy-6-(3,5-dimethyl-pyrazol-1-yl)-1,3,5-triazine) and dmp(3,5-dimethylpyrazole) are the alcoholysis products of bpt in the presence of Zn2+ ion. A possible mechanism for this catalytic reaction was proposed. X-ray crystal structure for ligand bpt, Ni and Zn complexes are reported. The protonated form of the ligand bpt crystallizes as its perchlorate salt including one molecule of water, [Hbpt · H2O · CIO4]. The proton is located on one pyrazole N-atom. [Hbpt ?H2O ?CIO4], in which [Hbpt]+ is in cis-cis conformation, are packed in slipped stacks of approximately parallel layers. The π-π overlap interactions between the non-protonized pyrazoles of the adjace 相似文献
908.
负载型过渡金属氧化物催化剂上SO_2的还原 总被引:1,自引:0,他引:1
研究了γ Al2 O3负载过渡金属氧化物催化剂上CO还原SO2 的反应 ,考察了系列过渡金属对该反应的催化活性 ,发现Fe系催化剂的性能最好。同时对还原反应的条件进行了选择 ,发现在较低温度下 ,大空速不利于SO2 的还原 ,而在较高温度下 ,气体空速对反应影响不大 ,不同的物料配比对反应结果有很大影响 ,当CO∶SO2 =2时 ,最有利于单质硫生成。研究证明 ,金属硫化物是催化SO2 还原反应的活性相 ,该活性相的形成与催化剂的氧化还原能力有关 ,整个还原反应的机理应为中间产物机理 相似文献
909.
910.
利用程序升温反应技术考察了cu交换度对Cu-Al-MCM-41上NO选择性还原反应性能的影响,同时结合XRD,N2吸附等温线,NMR,ICP-AES,TPD和TPR等技术对催化剂的结构特征和化学吸附性能进行了表征.结果表明,经Cu离子交换的Al-MCM-41并未改变载体的结构特征,仍保持长程有序的中孔结构.影响Cu-Al-MCM-41催化剂选择性还原活性的主要因素是Cu交换度,而不是Cu含量,前者决定了活性中心(主要是Cu^2 )的浓度.当Cu交换度低于100%时,随着Cu交换度的增加,NO最大转化率增加.当交换度超过100%后,催化剂的还原活性下降,此时出现的CuO起完全氧化的催化作用而非选择性还原的催化作用.在n(Si)/n(Al)=10,Cu交换度接近100%的Cu-Al-MCM-41上360℃时可获得79%的NO最大转化率. 相似文献