SiO2负载双氯基桥联双核Mo(V)催化剂合成、表征及其催化环己烯环氧化性能

合成了SiO2负载双氯基桥联双核Mo(V)催化剂,并用红外光谱、X-光电子能谱测定及UV-vis光谱等方法进行了结构表征.结果表明:SiO2负载双氯基桥联双核Mo(V)中金属Mo(V)离子以双齿配位形式与SiO2表面氧键合,双核Mo(V)间以μ-双氯基桥联.实验发现,其作为催化剂用于环己烯环氧化反应的活性组分是Mo(VI)而不是Mo(V).在反应过程中,经环氧化剂叔丁基过氧化氢(t-BuOOH)处理后,具有很高的催化活性和选择性;研究探讨了其催化环己烯环氧化的反应机理;建立了催化剂中Mo分析和环氧环己烷气相色谱分析新方法;在n(t-BuOOH)=0.1mol,n(C6H10) : n(t-BuOOH) = 3 : 1,溶剂5 mL,催化剂用量(以Mo计) ～0.0216 g,反应温度80℃,时间60min反应条件下,环氧环己烷收率(以t-BuOOH计)在99% 以上,质量分数～ 99.5 %(GC检测).催化剂循环使用5次后,未见活性明显下降,环氧环己烷收率(以t-BuOOH计)仍接近99%.     

等离子体-催化剂体系下甲苯加氢反应

探索了等离子体介质阻挡放电甲苯加氢工艺的行为。反应产物的气相色谱分析结果表明甲基环己烷为主产物。单因素实验法考察不同因素对甲苯加氢反应行为的影响,初步推测等离子体环境下甲苯加氢反应包含三种机理:加成反应、取代反应、C-C键断裂反应。研究发现,通过增大放电功率和催化剂(Ni/SiO2)协同作用,可使甲基环己烷转化率趋于最佳值。在反应条件为:"一段式"催化剂装填方式,0.30 g催化剂固载于0.1 g玻璃纤维上,催化剂活性金属组分含量17%(wt);放电电压8.4 k V;电极直径50 mm;气体配比(VH2/VC7H8)31;停留时间21 s,其甲苯转化率可达78.4%,甲基环己烷选择性72.2%。     

环己烷-正丁醇-甲苯三元体系加压相平衡研究

研究了环己烷、正丁醇、甲苯这类醇烃体系的加压汽液平衡行为.根据环己烷、正丁醇、甲苯有关二元体系求得的Wilson能量参数及统一关联式,预测了环己烷-正丁醇-甲苯三元体系在101～911kPa5个压力下的汽液平衡数据,与实测值符合良好.     

TG and DTA investigation of ZrO2–SO 4 2– catalysts exposed to hexane, methylcyclopentane and cyclohexane

ZrO₂– catalysts with different sulfur contents were analysed with thermal methods coupled with mass spectrometry after exposure to mixtures of hexane, methylcyclopentane, and cyclohexane in argon. The reaction of the hydrocarbons led to carbonaceous deposits, but an important part of hydrocarbon remained chemisorbed as well. Heating these samples in He atmosphere provoked the decomposition of these deposits with evolution of CO₂ and CO, and also of SO₂ and SO. At the same time, COS was evidenced in the reaction products. The release of these molecules occurred below the activation temperature of the catalysts. The behavior of the catalysts depended both on reactant molecule and sulfur content. The analyses clearly evidenced the oxidation ability of ZrO₂–SO catalysts. This revised version was published online in July 2006 with corrections to the Cover Date.     

水中痕量芳烃化合物的富集及测定

研究采用ＧＤＸ－３０１多孔微球为吸附剂，环己烷为脱附剂，富集水中痕量芳烃的条件。富集后的洗脱液直接注入２．０％ＤＮＰ－２．５％的有机皂士／１０１白色担体柱中，用ＦＩＤ检测器，恒温下进行气相色谱分离。采用单点校正法进行定量。大大提高了方法的灵敏度，已成功地应用于水中痕量芳烃化合物的测定。本法简便、快速，适用于微量、痕量杂质的富集测定。     

Viscosity of binary mixtures. I. mono-, di-, and tri-n-butyl and -n-octylamine with cyclohexane

Viscosities for six binary mixtures of n-butylamine, di-n-butylamine, tri-n-butylamine, n-octylamine, di-n-octylamine, and tri-n-octylamine with cyclohexane have been measured at 303.15 K with an Ubbelohde suspendedlevel viscometer. Deviations of viscosities from a rectilinear dependence on mole fraction are attributed to H-bonding and to the size of alkylamine compounds. The application of the Eyring's theory of activation energy is examined. The free volume theory of Prigogine-Flory-Patterson (PFP) and the experimental excess enthalpy have been used to estimate excess viscosity ln = (ln / ₁ ⁰ – x ₂ ln ₂ ⁰ / ₁ ⁰ ) and corresponding free volume, enthalpy, and entropy contributions for five binary mixtures of tri-n-alkylamine: triethyl, tripropyl, tributyl, trihexyl, and trioctylamine with cyclohexane. A comparison of experimental and theoretical excess viscosities indicates a failure of the PFP theory when two components of the mixture differ considerably in size. The size difference contribution to excess viscosity is related to (V ₂ ^*1/2 – V ₁ ^*1/2 ), where V ₁ ^* and V ₂ ^* are hard-core volumes of two components of the mixture.     

环氧环己烷的综合利用

介绍了几种从环已烷氧化副产物中提取环氧环己烷的工业回收方法，并对环氧环己烷的综合利用方法和前景作了评述和展望。     

用液－液萃取与精馏联合法分离叔戊醇－水共沸物

以一个单级的液－液萃取器与一个提馏塔结合分离具有共沸物的叔戊醇－水混合物。其中包括溶剂的选择、工艺方案和流程的确定、从极少文献中获得相平衡关联式参数、模拟计算方法和结果、工业化应用情况以及操作的稳定性和影响因素。     

Equations of State for Technical Applications. II. Results for Nonpolar Fluids

New functional forms have been developed for multiparameter equations of state for non- and weakly polar fluids and for polar fluids. The resulting functional forms, which were established with an optimization algorithm which considers data sets for different fluids simultaneously, are suitable as a basis for equations of state for a broad variety of fluids. The functional forms were designed to fulfill typical demands of advanced technical applications with regard to the achieved accuracy. They are numerically very stable and their substance-specific coefficients can easily be fitted to restricted data sets. In this way, a fast extension of the group of fluids for which accurate empirical equations of state are available becomes possible. This article deals with the results found for the non- and weakly polar fluids methane, ethane, propane, isobutane, n-butane, n-pentane, n-hexane, n-heptane, n-octane, argon, oxygen, nitrogen, ethylene, cyclohexane, and sulfur hexafluoride. The substance-specific parameters of the new equations of state are given as well as statistical and graphical comparisons with experimental data. General features of the new class of equations of state such as their extrapolation behavior and their numerical stability have been discussed in a preceding article. Results for typical polar fluids will be discussed in a subsequent article.     

Co-M/Al2O3上环己烷的选择性氧化研究

采用溶胶-凝胶法制备了Co-M/Al₂O₃(M=Cu，Zn，Ni)催化剂。在没有任何有机溶剂或助剂的条件下，研究了以空气为氧化剂的环己烷选择性氧化。所制备四种催化剂的活性为Co-Ni/Al₂O₃ >Co/Al₂O₃ >Co-Zn/Al₂O₃ >Co-Cu/Al₂O₃。在Co-Ni/Al₂O₃中Co、Ni的质量分数分别为4.0%和3.0%时活性最好。以Co-Ni/Al₂O₃为催化剂，在4.5 MPa、443 K下反应120 min，环己烷转化率达9.9%，环己酮和环己醇的总选择性达94.6%，n(酮)∶n(醇)为2.8。Co-Ni/Al₂O₃催化剂连续使用五次后活性基本不变。