含NS和NNSS供电子原子的钌(Ⅱ)羰基配合物

通过[RuHCl(CO)(PPh₃)₂(B)] (B=PPh₃, 吡啶 (py), 哌啶 (pip), 吗啉 (morph))与适当的席夫碱按1∶1的物质的量的比反应，合成了二齿和四齿席夫碱钌(Ⅱ)配合物。所用席夫碱配体通过S-苄基二硫代肼基甲酸酯与2,3-丁二酮(物质的量的比分别为1∶1和1∶2)的缩合反应制得。通过元素分析和多种物理化学方法对钌(Ⅱ)配合物和其席夫碱配体进行了表征。钌(Ⅱ)配合物为六配位的反磁性物质。用三种细菌对席夫碱配体及其钌(Ⅱ)配合物的抗微生物活性进行了筛选试验。     

Study on the variation of morphology and separation behavior of the stainless steel supported membranes at high temperature

Palladium composite membranes were prepared on stainless steel (SUS) supports modified by nickel submicron powder and colloidal silica sols. Permeation tests of the palladium composite membranes were carried out at high temperature in order to observe the thermal stability of the membrane. The palladium composite membrane failed with formation of plenty of pinholes in the presence of hydrogen at high temperature. The failure of the composite membrane was verified by comparing the nitrogen permeance before hydrogen permeation test with that after hydrogen permeation test and comparing the H₂/N₂ selectivity for single gas permeation test with that for mixture gas permeation test. The variation of the membrane surface due to the failure of the membrane was characterized in scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDS) analyses. As a result, it can be concluded that reducible metal oxides can be attributed to the failure of the composite membranes resulting from reduction of the metal oxides by hydrogen whichever position in the membrane the metal oxides are layered.     

Effects of diethyl aluminum chloride (DEAC) addition to the catalysts prepared by reduction of TiCl4 with EtMgCl on ethylene-propylene copolymerization

TiCl₃/2.5MgCl₂(0.5MgEt₂)/THF catalyst (R) was prepared by the reduction of TiCl₄ with EtMgCl. The effect of diethyl aluminum chloride (DEAC) addition on the catalytic activity in ethylene-propylene copolymerization was investigated. It was suggested from FT-i.r. that the catalyst R formed similar bimetallic (Ti-Mg-THF) complexes to the TiCl₃(AA)/3MgCl₂/THF catalyst (T3ME) of our previous report [7]. An ESR study provided evidence that the Ti³⁺ species in the catalyst R was of the multinuclear type, instead of an isolated type of T3ME, and it changed from a tetrahedral to an octahedral structure with addition of DEAC. The activities of R catalysts in copolymerization were more or less in the same order of magnitude with each other due to the multinuclear nature of the Ti³⁺ species, and the response to propylene comonomer decreased with addition of DEAC. The polydispersity of comonomer over R catalysts was in the range of 6–10, being much broader than that over the T3ME catalyst system. It might be due to the heterogeneity of the titanium(III) structure; tetrahedral as well as octahedral in R, instead of only octahedral in T3ME.     

Selective catalytic reduction of NO with CO on Pt/W–Ce–Zr catalysts

Various Pt catalysts (Pt/ZrO₂, Pt/CeO₂, Pt/CeZrO, Pt/WO₃/ZrO₂ and Pt/WO₃/CeZrO) were prepared and characterized, and their catalytic reduction reactions of NO by CO, with or without the presence of excess oxygen, were investigated. The results of temperature-programmed experiments showed that CO could be easily oxidized over Pt/CeO₂ and Pt/CeZrO while the introduction of WO₃ into the catalyst (Pt/WO₃/CeZrO) inhibited the reduction of catalyst surface; NO could not dissociate over those catalysts in oxidized state but after CO reduction at a low temperature, NO dissociation took place only over Pt/CeO₂ and Pt/CeZrO catalysts. For NO + CO reaction, those easily reduced catalysts Pt/CeO₂ and Pt/CeZrO exhibited better catalytic performances, and NO could be rapidly converted below 350 °C. For the reaction with the presence of excess O₂, the NO conversions were significantly inhibited, but better NO conversions were obtained over the tungstate-contained catalysts when compared with Pt/CeO₂ and Pt/CeZrO. The higher activities of Pt/W–Ce–Zr catalysts were attributed to their high acidities.     

Novel bidentate ruthenium(III) Schiff base complexes: synthetic,spectral, electrochemical,catalytic and antimicrobial studies

Ru^III complexes of the type [RuX(L)₂(E)] (X = Cl or Br; L = novel bidentate Schiff base ligand; E = PPh₃ or AsPh₃) have been prepared by reacting [RuX₃(E)₃] or [RuBr₃(PPh₃)₂(MeOH)] with two novel bidentate Schiff base ligands derived from 4-(1-methyl-1-mesitylcyclobutane-3-yl)-2-aminothiazole, in a 1:2 molar ratio in benzene, and characterised by analytical, spectral (i.r., electronic, ¹H-, ¹³C- n.m.r., and e.p.r.) and electrochemical data. An octahedral structure has been tentatively proposed for all the new complexes. The thermal properties of the ligands and their complexes have been studied by t.g.a. The new Ru^III complexes are effective catalysts for the oxidation of alcohols to carbonyl compounds but are unable to oxidise alkenes in the presence of N-methylmorpholine-N-oxide (NMO) as co-oxidant. The antimicrobial activity of the ligands and complexes have also been tested against six microorganisms.     

Study on methanol reforming–inorganic membrane reactors combined with water–gas shift reaction and relationship between membrane performance and methanol conversion

When a methanol reforming–membrane reactor is employed as a hydrogen generator for proton exchange membrane fuel cell (PEMFC), three important aims should be simultaneously achieved in one process, which are methanol conversion improvement, high hydrogen recovery, and high CO removal efficiency. To achieve the aims, we investigated five different configurations of a membrane reactor (a methanol reforming–microporous membrane (MMi) reactor, methanol reforming–mesoporous membrane (MMe) reactor, methanol reforming–mesoporous membrane–water–gas shift (MMeW) reactor, methanol reforming–macroporous membrane (MMa) reactor and methanol reforming–macroporous membrane–water–gas shift (MMaW) reactor). As a result, the MMi reactor was not suitable for a hydrogen carrier of PEMFC due to low hydrogen recovery. The MMe and MMa reactor showed low CO removal efficiency due to low permselectivity of the mesoporous and macroporous membrane. In contrast, the MMeW and MMaW reactor gave simultaneously methanol conversion improvement, high hydrogen recovery, and high CO removal efficiency in one process. The low CO removal efficiency due to low permselectivity of the mesoporous and macroporous membrane was significantly enhanced by the water–gas shift reaction in the permeate side of the MMeW and MMaW reactor. In addition, based on the reaction results in the MMi, MMe and MMa reactor, it was confirmed that methanol conversion in a membrane reactor system is higher as a membrane used in a membrane reactor has higher total permeance difference (∑permeance of products − ∑permeance of reactants).     

The studies of hydrodesulfurization activity over molybdenum catalysts supported on Al-MCM-41 modified by lanthanum

A series of lanthanum modified Al-MCM-41 substrates served as supports to prepare the Mo/La-Al-MCM-41 catalysts. The catalysts were characterized by XRD, BET, FT-IR, XPS, TPR and TPD, and their catalytic activities were determined for thiophene hydrodesulfurization (HDS).     

含NS和NNSS供电子原子的钌(Ⅲ)席夫碱配合物:催化性能和抗微生物活性

通过[RuX₃(EPh₃)₃] 或 [RuBr₃(PPh₃)₂(MeOH)] (式中X=Cl或Br; E=P或As)与适当的席夫碱以1∶1的物质的量的比反应合成了[RuX₂(L′)(EPh₃)₂]或[RuX(LL′)(PPh₃)](式中L′=席夫碱配体1，即[S-benzyl     

Characteristics of metallic iron in Y-zeolite catalysts reduced by hydrogen atom beams

Hydrogen atom beams were used to reduce the ionic species of iron-Fe(II) and Fe(III) in Y-zeolite. Reduction to metallic states was confirmed by ferromagnetic resonance (FMR) spectroscopy, and the catalytic activity in CO hydrogenation showed high selectivity towards ethylene and butene.     

New group 4 half sandwich complexes containing triethanolamine ligand for polyethylene

(η⁵-C₅Me₅)M(TEA) (M = Ti, 1; Zr, 2; Hf, 3; TEA = triethanolateamine) was prepared by the reaction of (η⁵-C₅Me₅)MCl₃ with triethanolamine in the presence of NEt₃. The polyethylene catalytic efficiency in terms of activity decreases in the order 1/MAO > 2/MAO ? 3/MAO. In addition, the molecular weight (M_v) and melting temperature (T_m) of all the resulting polyethylene obtained by 2/MAO show the range of M_v = 91,200-356,200 and T_m = 137.0-141.9 °C, respectively; however, 1/MAO and 3/MAO gave polyethylenes with lower molecular weight (M_v = 6800-78,700) and lower melting temperature (T_m = 125.9-136.7 °C). Furthermore, 1/MAO showed significant decrease in the catalytic activity with increasing polymerization temperature though 2/MAO and 3/MAO have no dependence on the polymerization temperature.