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1 INTRODUCTION In the past decades, metal disulphides have recei- ved much attention due to their diversity struc- tures[1~4] and applications as potential ligands for metal ions in biological system[5]. Metal disulfide compounds are usually prepared from the direct reactions of metal ions with organic disulphide[1~5], while some others are isolated from the reactions of metal salts and thiolates with the presence of certain oxidizing agents (e.g., O2, H2O2, etc.)[6, 7]. A large number o… 相似文献
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Johannes Ihli Leonid Bloch Frank Krumeich Klaus Wakonig Mirko Holler Manuel Guizar‐Sicairos Thomas Weber Julio Cesar da Silva Jeroen Anton van Bokhoven 《Angewandte Chemie (International ed. in English)》2020,59(39):17266-17271
Hydrodesulphurization, the removal of sulphur from crude oils, is an essential catalytic process in the petroleum industry safeguarding the production of clean hydrocarbons. Sulphur removal is critical for the functionality of downstream processes and vital to the elimination of environmental pollutants. The effectiveness of such an endeavour is among other factors determined by the structural arrangement of the heterogeneous catalyst. Namely, the accessibility of the catalytically active molybdenum disulphide (MoS2) slabs located on the surfaces of a porous alumina carrier. Here, we examined a series of pristine sulfided Mo and NiMo hydrodesulphurization catalysts of increasing metal loading prepared on commercial alumina carriers using ptychographic X‐ray computed nanotomography. Structural analysis revealed a build consisting of two interwoven support matrix elements differing in nanoporosity. With increasing metal loading, approaching that of industrial catalysts, these matrix elements exhibit a progressively dissimilar MoS2 surface coverage as well as MoS2 cluster formation at the matrix element boundaries. This is suggestive of metal deposition limitations and/ or catalyst activation and following prohibitive of optimal catalytic utilization. These results will allow for diffusivity calculations, a better rationale of current generation catalyst performance as well as a better distribution of the active phase in next‐generation hydrodesulphurization catalysts. 相似文献
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分别用稀土醋酸盐和稀土高氯酸盐与希弗碱配体和巯基烟酸配体反应得到了两例镝配合物[Dy2(OAc)6H2O]n(1)和{[DyL(H2O)4]ClO4·H2O}n(2)(L=2,2'-二硫代-二(3-吡啶甲酸)),并通过单晶X-射线衍射、元素分析、红外光谱和磁性测试对其进行了表征。结构研究和磁性测试表明:化合物1是羧基桥连的一维链结构,该化合物表现出慢磁弛豫性质,有效能垒为2 K;化合物2是通过原位生成的二硫键桥连的二维网状结构,表现出明显的铁磁相互作用和慢磁弛豫行为。 相似文献
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An analytical method was developed to measure the concentration of hydrogen sulphide, methyl mercaptan, dimethyl sulphide and dimethyl disulphide contained in aqueous matrices (distilled water, tap water, kraft mill condensates and membrane bioreactor mixed liquor) by direct injection of aqueous samples into a gas chromatograph with a flame photometric detector. The analytical method requires a small sample volume (2 ml), sample preparation and analysis can be completed within 20 min and no complex sampling apparatus is needed. Consistent results and good recoveries were observed in all matrices investigated over the range of concentrations examined. The relationship between the normalized peak area obtained from GC–flame photometric detection and the concentration of the reduced sulphur compounds (RSCs) examined did not follow the theoretical power law exponent of two. The power law exponent appeared to decrease with the organic fraction associated with each RSC. The observed power law exponents for hydrogen sulphide, methyl mercaptan, dimethyl sulphide and dimethyl disulphide were 1.92, 1.90, 1.66 and 1.72, respectively. 相似文献
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Mas JM Aloy P Martí-Renom MA Oliva B de Llorens R Avilés FX Querol E 《Journal of computer-aided molecular design》2001,15(5):477-487
The preferential occurrence of certain disulphide-bridge topologies in proteins has prompted us to design a method and a program, KNOT-MATCH, for their classification. The program has been applied to a database of proteins with less than 65% homology and more than two disulphide bridges. We have investigated whether there are topological preferences that can be used to group proteins and if these can be applied to gain insight into the structural or functional relationships among them. The classification has been performed by Density Search and Hierarchical Clustering Techniques, yielding thirteen main protein classes from the superimposition and clustering process. It is noteworthy that besides the disulphide bridges, regular secondary structures and loops frequently become correctly aligned. Although the lack of significant sequence similarity among some clustered proteins precludes the easy establishment of evolutionary relationships, the program permits us to find out important structural or functional residues upon the superimposition of two protein structures apparently unrelated. The derived classification can be very useful for finding relationships among proteins which would escape detection by current sequence or topology-based analytical algorithms. 相似文献
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大气颗粒物对CS2催化氧化反应动力学研究 总被引:8,自引:0,他引:8
使用FTIR, XPS, BET, TG-DTG-DTA及原位XRD等方法研究了二硫化碳(CS2)在大气颗粒物表面多相催化反应历程及硫物种的转化过程. 结果表明, 在常温下, CS2能与大气颗粒物反应, 主要产物有羰基硫(COS)和正交α-S8, 少量硫物种被深度氧化, 在大气颗粒物表面形成正六价态硫. 反应体系中当氧气过量时, CS2在大气颗粒物表面多相催化反应遵循假二级反应动力学规律. 在296 K下, 该反应的表观速率常数为6.98×10-22 cm3*mol-1*s-1, 表观活化能为34.6 kJ/mol, 揭示了大气颗粒物具有消除CS2的重要作用以及深度氧化使颗粒物表面形成SO2-4的现象. 相似文献
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P Kistaiah Y C Venudhar K Sathyanarayana Murthy Leela Iyengar K V Krishna Rao 《Pramana》1981,16(4):281-286
The lattice parameters of the compound copper indium disulphide (CuInS2) have been measured by x-ray diffraction. The data have been used to evaluate the coefficients of thermal expansion, perpendicular
and parallel to the principal axis. The thermal expansion studies revealed the anisotropy between the axial expansion coefficients
having a larger coefficient of expansion alonga axis than that alongc axis. The anisotropic thermal expansion of this compound is interpreted in terms of the thermal expansion of the Cu-S and
In-S bonds. 相似文献
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Herein, for the first time, a new generation cysteine modified MoS2 (Cys@MoS2) based electrochemical sensor was reported. The electrochemical behaviour of dapagliflozin (DAP) was investigated through differential pulse voltammetry (DPV) on the developed sensor (Cys@MoS2/GCE). The transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), x‐ray diffraction spectroscopy (XRD) and x‐ray photoelectron spectroscopy (XPS) methods were performed for structural and morphological characterizations of Cys@MoS2 nanocomposite. On the surface of Cys@MoS2/GCE, an irreversible anodic peak was observed at 1324 mV. Under the optimal conditions, linear calibration curve with two working ranges between 2.0–60.0 μM and 60.0–110.0 μM were obtained and limit of detection was found to be 1.6 μM. The developed sensor was successfully applied to determine the content of DAP in pharmaceutical sample with satisfying recovery results. It is concluded that Cys@MoS2/GCE is a reliable, easy to apply and cost‐effective sensor for the routine DAP analysis in pharmaceutical samples. 相似文献
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S. Pandey E. Fosso-Kankeu M.J. Spiro F. Waanders N. Kumar S.S. Ray J. Kim M. Kang 《Materials Today Chemistry》2020
This work explored the potential of clinoptilolite, molybdenum sulphide (MoS2), and MoS2-clinoptilolite composite in lead (Pb) removal from aqueous medium and industrial mining wastewater. MoS2-clinoptilolite composite was successfully prepared by a hydrothermal method. The surface properties, structure, and composition of the synthesized composite and the parent compounds were analyzed by scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. The removal efficiency of lead from aqueous solution was studied in batch-mode experiments. The MoS2-clinoptilolite was used for the removal of Pb ions (50 mg/L) from an aqueous solution: ~100% of the Pb was removed with a MoS2-clinoptilolite dose of 0.075 g, pH 6 at 328K within 90 min. The adsorption capacities of Pb onto MoS2-clinoptilolite were found to be higher than those onto clinoptilolite. Metal ion adsorption behavior was well explained by the Freundlich model, that is, multilayer adsorption of Pb molecules occurred on the heterogeneous surface of adsorbents in case of clinoptilolite, while in the case of MoS2-clinoptilolite, the Langmuir model was suitable, that is, the adsorption occurred on a monolayer surface. The rate of Pb adsorption was explained by pseudo-second-order model suggesting that the adsorption process is presumably chemisorption. Thermodynamic parameters such as ΔH°, ΔS°, and ΔG° were calculated, which indicated that the adsorption was spontaneous and exothermic in nature. The selectivity of each adsorbent for Pb was also tested by adding the adsorbents to real gold mine water which contains competitive metal ions. 相似文献