多乙苯脱氢制多乙烯苯氧化铁催化剂的研究助剂钾,铈对催化性能的影响

研制了适合多乙苯脱氢制多乙烯苯的Ｆｅ－Ｋ－Ｃｅ复合型脱氢催化剂．助剂钾以钾霞石（ＫＡｌＳｉＯ４）方式引入，既克服了钾的大量流失，又保留了钾碱的抗积炭性能，使催化剂活性稳定．另一助剂ＣｅＯ２的加入对催化剂中的各组分起到了一定的分散作用，使催化剂晶粒度变小，并且提高了活性组分Ｆｅ２Ｏ３的还原温度，因而可增强催化剂的抗还原能力．     

Electrochemical reduction and voltammetric determination of metronidazole at a nanomaterial thin film coated glassy carbon electrode

Simple and sensitive electrochemical method for the determination of metronidazole, based on a nanostructured film coated glassy carbon electrode (GCE), is described. Multi-walled carbon nanotubes (MWNT) was dispersed into water in the presence of a hydrophobic surfactant to give very stable and homogeneous MWNT suspension, and a MWNT-film coated GCE was achieved via evaporating solvent. Metronidazole yields a well-defined reduction peak whose potential is −0.71 V at the MWNT-film coated GCE in pH 9.0 Britton-Robinson buffer. Compared with bare GCE, the MWNT-film modified GCE significantly enhances the reduction peak current of metronidazole. All the experimental parameters were optimized for the determination of metronidazole. The detection limit is 6×10⁻⁹ mol/l at 2 min accumulation. This method has been successfully used to determine metronidazole in the drugs. Furthermore, results obtained by the proposed method have been compared with spectrophotometric method.     

Pd_2(dba)_3/BINAP催化合成1,4-双-(4′-苯胺基苯酰基)苯

以Pd2(dba)3/BINAP催化1,4-双-(4′-溴苯酰基)苯和苯胺反应,合成了1,4-双-(4′-苯胺基苯酰基)苯,其结构经UV,1HNMR,13CNMR和元素分析表征。     

MCM-41-supported bidentate phosphine palladium(0) complex: a highly active and recyclable catalyst for the Sonogashira reaction of aryl iodides

The first MCM-41-supported bidentate phosphine palladium(0) complex has been prepared. This complex is a highly efficient catalyst for Sonogashira reaction and can be reused at least 10 times without any decrease in activity.     

Preparation of Layer Structure-Controlled Ru-Sn-Al2O3 Catalysts and Their Reactivity

In order to achieve functional group selective hydrogenation, the layer structure of Ru-Sn-Al2O3 catalysts was controlled by using sol-gel, powder impregnation and combined sol-gel impregnation methods. The properties of the catalysts and effectiveness in hydrogenation of dimethyl terephthalate were examined. The surface Sn contents of the catalysts characterized by X-ray photoelectron spectroscopy depended on the preparation method, in spite of almost the same bulk Ru and Sn compositions measured by X-ray fluorescence analyses. TPR and CO adsorption of the catalysts also depended on the preparation method. With regard to the conversion rate of dimethyl terephthalate and the rate of product conversion from methyl 4-hydroxy methylbenzoate to p-xylene via methyl p-toluate, Ru impregnation catalysts had higher rates than the other catalysts.     

三效催化剂作用下的NO+CO催化反应机理

NO与CO在Pt/Rh/Pd及载体组成的三效催化剂上的氧化还原应用是控制汽车尾气对空气污染的一个关键反应，这一反应随着近年来对环境保护的日益重视而成为国内外研究的热点，本文主要综述了NO及CO在Pt,Rh,Pd上的吸附及反应机理的实验及理论研究现状，总结得出：在三效催化剂对NO CO的催化反应中，Pt,Pd对CO的催化氧化起主要作用，而Rh对NO的解离有很好的活化作用。     

手性钯络合物催化下2-硝基环酮的不对称烯丙基化反应

在用氮杂冠醚改良的手性二茂铁膦与钯的络合物催化下, 2-硝基环酮可进行不对称烯丙基化反应. 讨论了配位基的形状, 反应物的构造, 碱的类型以及反应时间对反应速率和立体选择性的影响. 通过增加反应的空间位阻改进了反应的立体选择性 .     

The high-temperature durability of Rh-free threeway catalysts used for automoble emission control

The high-temperature durability of cordierite honeycomb Rh-free three-way catalysts (TWC) containing additives has been studied by calcining catalysts at various temperatures in the interval of 600≈1100°C. The three-way performances of these catalysts were evaluated for the reaction of carbon monoxide(CO), hydrocarbon(HC) and nitrogen oxides(NOx) at given conditions by using a fixed bed reactor. The results show that after Rh-free TWC are thermally aged in air at 1100°C for 5h and 950°C for 104 h, the TWC still have better three-way activity compared with Rh-containing TWC.     

Dawson型磷钨酸催化合成乳酸月桂醇酯

用Dawson型磷钨酸催化合成乳酸月桂醇酯。实验结果表明:Dawson型磷钨酸有较高的催化活性,反应时间短,酯收率高,工艺简单。最佳工艺条件为:醇/酸摩尔比为1.5:1,催化剂用量为0.3%,带水剂甲苯体积(mL)与反应物质量(g)之比为0.4:1~0.5:1,反应温度为115~140℃,反应时间30~50min。在此条件下,酯收率可超过93% 。     

Kinetics of Hydroperoxide Epoxidation of 1-Octene in the Presence of MoB2

We have studied the kinetics of the process of epoxidation of 1-octene by tert-butyl hydroperoxide in the presence of molybdenum boride MoB₂. We have studied the effect of the concentrations of starting materials and reaction products on the process. We suggest a kinetic scheme and we calculate the kinetic parameters of the process.