羰基铁－硫醇（硫酚）－格氏试剂体系与芳酰氯反应的研究──某些μ－芳酰基铁硫配合物的合成及结构

通过Ｆｅ３（ＣＯ）（１２）、硫醇（硫酚）和ＥｔＭｇＢｒ所形成的络盐［（μ－ＣＯ）（μ－ＲＳ）Ｆｅ２（ＣＯ）６］－Ｍｇ＋Ｂｒ与氯代芳酰氯的原位反应，合成了通式为（μ－ＲＳ）（μ－ｏ－ＣｌＣ６Ｈ４ＣＯ）Ｆｅ２（ＣＯ）６和（μ－ＲＳ）（μ－ｍ－ＣｌＣ６Ｈ４ＣＯ）Ｆｅ２（ＣＯ）６（Ｒ＝ｎ－Ｒｕ，ｔ－Ｂｕ，Ｐｈ）的６个新桥芳酰基铁硫配合物，并用Ｃ／Ｈ分析、ＩＲ和１ＨＮＭＲ表征了它们的结构。

Effects of zinc on Fe-based catalysts during the synthesis of light olefins from the Fischer-Tropsch process

Fe‐based catalysts for the production of light olefins via the Fischer‐Tropsch synthesis were modi‐fied by adding a Zn promoter using both microwave‐hydrothermal and impregnation methods. The physicochemical properties of the resulting catalysts were determined by scanning electron mi‐croscopy, the Brunauer‐Emmett‐Teller method, X‐ray diffraction, H2 temperature‐programed re‐duction and X‐ray photoelectron spectroscopy. The results demonstrate that the addition of a Zn promoter improves both the light olefin selectivity over the catalyst and the catalyst stability. The catalysts prepared via the impregnation method, which contain greater quantities of surface ZnO, exhibit severe carbon deposition following activity trials. In contrast, those materials synthesized using the microwave‐hydrothermal approach show improved dispersion of Zn and Fe phases and decreased carbon deposition, and so exhibit better CO conversion and stability.

Effects of Potassium and Manganese Promoters on Nitrogen-Doped Carbon Nanotube-Supported Iron Catalysts for CO_2 Hydrogenation

Nitrogen-doped carbon nanotubes （NCNTs） were used as a support for iron （Fe） nanoparticles applied in car- bon dioxide （CO_2） hydrogenation at 633 K and 25 bar （1 bar = 10-5 Pa）. The Fe/NCNT catalyst promoted with both potassium （K） and manganese （Mn） showed high performance in CO_2 hydrogenation, reaching 34.9% conversion with a gas hourly space velocity （GHSV） of 3.1 L-（g·h）-1. Product selectivities were high for olefin products and low for short-chain alkanes for the K-promoted catalysts. When Fe/NCNT catalyst was promot- ed with both K and Mn, the catalytic activity was stable for 60 h of reaction time. The structural effect of the Mn promoter was demonstrated by X-ray diffraction （XRD）, temperature-programmed reduction （TPR） with molecular hydrogen （H2）, and in situ X-ray absorption near-edge structure （XANES） analysis. The Mn pro- moter stabilized wtistite （FeO） as an intermediate and lowered the TPR onset temperature. Catalytic ammo- nia （NH_3） decomposition was used as an additional probe reaction for characterizing the promoter effects. The Fe/NCNT catalyst promoted with both K and Mn had the highest catalytic activity, and the Mn-promoted Fe/NCNT catalysts had the highest thermal stability under reducing conditions.

Comparison of wear behaviour of LM13 Al−Si alloy based composites reinforced with synthetic(B_(4)C)and natural(ilmenite)ceramic particles

Dry sliding wear behaviour of stir-cast aluminium matrix composites(AMCs)containing LM13 alloy as matrix and ceramic particles as reinforcement was investigated.Two different ceramic particle reinforcements were used separately:synthetic ceramic particles(B_(4)C),and natural ceramic particles(ilmenite).Optical micrographs showed uniform dispersion of reinforced particles in the matrix material.Reinforced particles refined the grain size of eutectic silicon and changed its morphology to globular type.B_(4)C reinforced composites(BRCs)showed maximum improvement in hardness of AMCs.Ilmenite reinforced composites(IRCs)showed maximum reduction in coefficient of friction values due to strong matrix−reinforcement interfacial bonding caused by the formation of interfacial compounds.Dry sliding wear behaviour of composites was significantly improved as compared to base alloy.The low density and high hardness of B_(4)C particles resulted in high dislocation density around filler particles in BRCs.On the other hand,the low thermal conductivity of ilmenite particles resulted in early oxidation and formation of a tribo-layer on surface of IRCs.So,both types of reinforcements led to the improvement in wear properties of AMCs,though the mechanisms involved were very different.Thus,the low-cost ilmenite particles can be used as alternative fillers to the high-cost B_(4)C particles for processing of wear resistant composites.

Iron-based Fischer-Tropsch Synthesis Catalyst Achieves an Alcohol Selectivity Exceeding 60%

The key project'Nano-scale catalyst and related process research and development activity for high-efficiency synthesis of mixed lower alcohols from syngas'undertaken by the Shanghai Senior Research Institute of CAS has passed the acceptance tests by the expert group organized by the Shanghai Science and Technology Commission.

New strategy for reversing biofilm-associated antibiotic resistance through ferrocene-substituted carborane ruthenium(Ⅱ)-arene complex

Bacterial biofilms are inherently resistant to antimicrobial agents and are difficult to eradicate with conventional antimicrobial agents, resulting in many persistent and chronic bacterial infections. In this contribution, a new strategy for reversing the biofilm-associated antibiotic resistance has been explored by induction of a carborane ruthenium(II)-arene complex (FcRuSB). Our results demonstrate that the FcRuSB could be utilized as an inducer to efficiently reverse the biofilm-associated antibiotic resistance of multidrug-resistant (MDR) clinical isolates of Staphylococcus aureus and Pseudomonas aeruginosa. The induced effect of FcRuSB is correlated with a considerable decrease in the expression of extracellular matrix proteins (EMP) of the two strains. The considerable decrease of the EMP of induced cells, resulting in the reduction of adherence and biofilm formation ability of the two types of MDR pathogens, and then can cause significantly enhanced sensitivity of them to antibiotics.