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1.
采用溶胶-凝胶-程序升温溶剂热一步法,利用表面活性剂EO20PO70EO20(P123)作为模板剂,分别制备了三元纳米复合材料Ag/ZnO-TiO2、Ag/Al2O3-TiO2和Ag/Fe2O3-TiO2。通过XRD、氮气吸附-脱附测定、TEM以及扫描电子显微镜配合X-射线能量色散谱仪(SEM-EDS)等对合成的3种催化剂进行了对比表征分析。结果表明,复合材料Ag/MxOy-TiO2中Ag以单质形式存在并较好地分布在MxOy-TiO2表面上。所合成产物颗粒尺寸较小(约10 nm左右),形貌较好。其中,Ag/ZnO-TiO2的比表面积与Ag/Al2O3-TiO2十分相近,略大于Ag/Fe2O3-TiO2。光催化活性研究中,以甲基橙为模型分子且辅以微波场作用。结果显示,上述三元复合材料的活性均明显高于未掺杂银的二元复合材料,其中Ag/ZnO-TiO2的光催化活性最好,在90 min内对甲基橙的降解率高达86%。 相似文献
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The thermal behaviour of [Co(en)n(phen)m]Cl3 complexes has been studied using thermogravimetry (TG), differential thermogravimetry (DTG) and differential thermal analysis (DTA) in air, nitrogen and oxygen atmospheres. The effect of the stoichiometry of the complexes and that of the gas atmosphere in the furnace chamber on the thermal decomposition reaction is evidenced and discussed. The following thermal stability order has been found [Co(en)3]Cl3 [Co(en)2(phen)]Cl3 > [Co(en)(phen)2]Cl3 [Co(phen)3]Cl3 相似文献
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Heats of formation for ClO3, ClO4, Cl2O3, Cl2O4, Cl2O5, Cl2O6 and Cl2O7 molecules are determined at the B3LYP, B3PW91, mPW1PW91 and B1LYP levels of the density functional theory employing a series of extended basis sets, and using Gaussian-3 model chemistries. Modified Gaussian-3 calculations, which employ accurate B3LYP/6-311+G(3d2f) molecular geometries and vibrational frequencies, were also performed. Heats of formation were calculated from both total atomization energies and isodesmic reaction schemes. The latter method in conjunction with Gaussian-3 models leads to the most reliable results. The best values at 298 K for ClO3, ClO4, Cl2O3 and Cl2O4 as derived from an average of G3//B3LYP and G3//B3LYP/6-311+G(3d2f) calculations are 43.1, 54.8, 31.7 and 37.4 kcal mol−1. From calculations carried out at the G3(MP2)//B3LYP and G3(MP2)//B3LYP/6-311+G(3d2f) levels, heats of formation for Cl2O5, Cl2O6 and Cl2O7 are predicted to be 53.2, 52.2 and 61.5 kcal mol−1. All best values are reproduced within 1 kcal mol−1 by using mPW1PW91/6-311+G(3d2f) isodesmic energies. Enthalpy changes for relevant Cl–O bond fission reactions are reported. Comparisons with previous thermodynamics data are made. 相似文献
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Absolute cross sections were measured for beam attenuation, MX+(1Σg+) chemiionization and MX(A2Π) chemiluminescence. The latter disagree strikingly with predictions based on adiabatic correlations. Information theoretic analysis shows some channels to be statistically, other highly non-statistically populated. A qualitative MO model is in accord with these findings. 相似文献
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以Nix/zMgy/zAl2/z(OH)2(CO3)1/z(z=x+y+2,x=0.2、1,5≤y≤11.8)水滑石为前驱体,经高温焙烧和H2还原后得到了一系列可用于甲醇-丁酮(MEK)烷基化反应的Nix/MgyAl2Oy+3(x=0.2、1,5≤y≤11.8)双功能催化剂,并采用X射线衍射(XRD)、透射电子显微镜(TEM)、程序升温还原(TPR)、程序升温脱附(TPD)等技术对催化剂的结构和形貌进行了表征。活性实验结果发现Ni/Mg9Al2O12催化剂具有较好的活性,在常压、温度280℃、原料液时空速(LHSV)6.0 h-1的条件下,丁酮的转化率为61.6%,3?戊酮(DEK)和3?甲基?2?丁酮(MIPK)的选择性分别为45.0%和17.7%。表征结果表明催化剂中合适的活性金属Ni和MgO含量对提高DEK和MIPK的选择性具有重要的影响,Ni与催化剂表面碱量之间的协同作用可能是影响催化剂的活性和选择性的主要因素。 相似文献
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A. P. Kharitonov A. P. Suetinov Yu. L. Moskvin 《Reaction Kinetics and Catalysis Letters》1980,15(3):305-310
Critical phenomena in the flash photolysis of gaseous mixtures: 1. Cl2–H2 with added O2 and HCl, and 2. Cl2–F2 have been studied by kinetic spectroscopy to measure the rate constants of the processes: Cl+H2HCl+H, Cl+F2ClF+F and Cl+O2+MClO2+M.
: I. Cl2–H2 O2 HCl II. Cl2–F2 : Cl+H2HCl+H, Cl+F2ClF+F, Cl+O2+MClO2+M.相似文献
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用HF自洽场理论和密度泛函理论(DFT)的B3LYP方法,在6 31G水平上研究了低聚物(Cl2AlNH2)n和(H2AlNH2)n(n=1~5)簇的几何构型、电子结构和聚合反应热力学性质,比较了两个系列化合物中化学键的强度.结果表明,Cl2AlNH2和H2AlNH2分子为C2 (EC)平面型结构,其中Al-N为由一个σ键和一个键组成的双键.(Cl2AlNH2)n和(H2AlNH2)n(n=1~5)分子为Dnh对称,Al-N是典型的σ单键 .低聚物(Cl2AlNH2)n和(H2AlNH2)n的稳定性顺序分别为: 3 > 2 > 4> 5 > 1和8 > 7 > 9 > 11 > 6. 相似文献
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A. E. Galashev V. N. Chukanov A. N. Novruzov O. A. Novruzova 《Russian Journal of Electrochemistry》2007,43(2):136-145
Molecular dynamics method is used for studying complex permittivity ɛ and the stability of individual water clusters as a
function of the number of involved molecules (7 ≤ i ≤ 20) and also the corresponding characteristics of water aggregates with a captured CO2 or CH4 molecule. Absorption of the latter molecules leads to considerable changes in dielectric properties and stability of clusters.
In particular, upon the addition of a CO2 molecule to a water cluster, the oscillation parameters of the real and imaginary parts of the permittivity change. Capture
of a CH4 molecule by a water aggregate changes the ɛ(ω) dependence from the relaxation to resonance type. For i ≥ 15, the thermal stability of individual water clusters can be lower than that of aggregates CO2(H2O)
i
and CH4(H2O)
i
. The mechanical stability of (H2O)
i ≥ 13 clusters can exceed that of heteroclusters under consideration. Clusters (H2O)
i
and CO2(H2O)
i
have approximately the same dielectric stability, whereas aggregates CH4(H2O)
i
exhibit lower stability with respect to electric perturbations.
Original Russian Text ? A.E. Galashev, V.N. Chukanov, A.N. Novruzov, O.A. Novruzova, 2007, published in Elektrokhimiya, 2007,
Vol. 43, No. 2, pp. 143–153. 相似文献
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Two new quaternary strontium selenium(IV) and tellurium(IV) oxychlorides, namely, Sr3(SeO3)(Se2O5)Cl2 and Sr4(Te3O8)Cl4, have been prepared by solid-state reaction. Sr3(SeO3)(Se2O5)Cl2 features a three-dimensional (3D) network structure constructed from strontium(II) interconnected by Cl−, SeO32− as well as Se2O52− anions. The structure of Sr4(Te3O8)Cl4 features a 3D network in which the strontium tellurium oxide slabs are interconnected by bridging Cl− anions. The diffuse reflectance spectrum measurements and results of the electronic band structure calculations indicate that both compounds are wide band-gap semiconductors. 相似文献
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Hai-Long Jiang 《Journal of solid state chemistry》2006,179(6):1911-1917
Two new barium zinc selenite and tellurite, namely, BaZn(SeO3)2 and BaZn(TeO3)Cl2, have been synthesized by the solid state reaction. The structure of BaZn(SeO3)2 features double chains of [Zn(SeO3)2]2− anions composed of four- and eight-member rings which are alternatively along a-axis. The double chains of [Zn2(TeO3)2Cl3]3− anions in BaZn(TeO3)Cl2 are formed by Zn3Te3 rings in which each tellurite group connects with three ZnO3Cl tetrahedra. BaZn(SeO3)2 and BaZn(TeO3)Cl2 are wide bandgap semiconductors based on optical diffuse reflectance spectrum measurements. 相似文献
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G. H. Pieters B. J. Van der Veken M. A. Herman 《Journal of Molecular Structure》1983,102(3-4):221-233
The gas phase infrared- and far infrared spectra of the normal and totally deuterated molecules have been recorded and are briefly discussed.
Rigid-rotor asymmetric top profiles for gauche and trans conformers were used to simulate the experimental gas phase infrared absorption profiles of four conformational doublets of CH3OP(O)Cl2. From this, a consistent assignment of the more intense component of each doublet to the gauche, and the less intense component to the trans conformer, is deduced. 相似文献
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The ethylene butadiene copolymerization with systems of three components Al[N(CH3)2]3, Al(C2H5)Cl2 and VOCl3 or VCl4, is described. In the resulting copolymers, the butadiene units are substantially in trans-1,4 configuration. Although it is possible to obtain copolymers with a wide range of composition, attention was paid to products with a low content of unsaturation (less than 2% mole of butadiene). These copolymers are highly homogeneous. They show high crystallinity of the polyethylene type and they can be crosslinked with conventional sulphur recipes. 相似文献
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Chemiluminescent reactions involving copper and halogen molecules are shown to result from the bimolecular reaction of metastable Cu(2D) with Cl2, Br2, and I2 under single-collision conditions. The collision-energy dependence of the reactions is described by a hard-sphere model with zero threshold energy. Cross sections for these reactions are compared with that for chemiluminescent reaction of Cu(2S) with F2. 相似文献
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It is found that charge-transfer on NO−2 with Cl2 is fast at thermal energy. The Cl−2 ion reacts with NO2 to produce Cl− and NO2Cl, and SH− charge-transfers rapidly with both Cl2 and NO2. From the exothermicities implied it is deduced that EA (SH)<EA (NO2)< EA (Cl2) or EA (NO2) = 2.38 ± 0.06 eV and EA (Cl2 = 2.46 ± 0.14 eV. 相似文献
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Alex D. Sun 《Journal of fluorine chemistry》2010,131(11):1237-19511
PtCl2(DMSO)2 has been identified as a readily accessible and effective C-F activation precatalyst. We report herein the study of reaction optimization and substrate scope. A comparison is made with previously reported [Pt2Me4(SMe2)2] and PtCl2(SMe2)2 precatalysts. 相似文献
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The reaction of Zn(NO3)2·6H2O with PPz hexahydrate (PPz=piperazine) and NH4SCN in CH3OH afforded the complex [Zn(NCS)2(PPz)]n (1). The reaction of CoCl2·6H2O with PPz in CH3OH afforded the complex [CoCl2(PPz)]n (2). The PPz ligand in 1 is coordinated to the metal centers through both nitrogen atoms to form a 1-D zigzag-chain structure and the distorted tetrahedral coordination geometry at each zinc center is completed by a pair of N-bonded thiocyanate ligands. Compound 2 has an analogous 1-D zigzag-chain structure containing terminal chloro ligands. Important NCSH---N hydrogen-bonding interactions in compound 1 and N---HCl---M and C---HCl---M hydrogen-bonding interactions in compound 2 play a significant role in aligning the polymer strands in the crystalline solid. 相似文献
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Diazoaminobenzene (DAAB) formed slowly when aniline was reacted with Zn(py)2(ONO)2 in dichloroethane at 60°. The rate of reaction was followed by measuring the DAAB concentration spectrophotometrically at 353 nm. Complex concentrations ranged from 5 to 30 mM, while those of aniline were from 100 to 900 mM. The kinetic data were explained by a mechanism involving a pre-equilibrium, wherein aniline displaced a nitrite ion from the zinc complex. This was followed by a slow reaction of the free nitrite ion with the solvent, forming a highly reactive nitrosating species. 相似文献