含铜过渡金属水滑石类化合物对苯酚过氧化氢羟化的催化作用

合成了一系列二元、三元过渡金属水滑石类化合物, 并经XRD、IR进行了表征.苯酚过氧化氢羟化结果表明, 含铜水滑石类化合物对该反应有较高的催化活性, 并初步提出了反应机理.     

在La-TiO2催化剂上由苯酚直接氧化制取邻苯二酚的研究

以Ｌａ－ＴｉＯ２作为苯酚选择氧化催化剂,用过氧化氢氧化,得到邻苯二酚选择性高达９０％的良好结果,讨论了溶剂,反应温度,反应时间,过氧化氢浓度,催化剂用量,过氧化氢用量等工艺条件对苯酚羟基化作用的影响。     

用胶束电动毛细管色谱法测定海洋沉积物中苯系物

海洋沉积物中苯系物的分析和测量对海洋石油化探具有重要意义。作者用胶束电动毛细管色谱法对海洋沉积物中苯系物进行了测定。考察了十二烷基硫酸钠 (SDS)的浓度和有机添加剂对分离的影响以及影响峰面积重现性和迁移时间的因素。苯系物的浓度和对应的峰面积成良好的线性关系。将该法用来分析石油勘探远景区域海洋沉积物中的苯系物 ,得到了它们的含量范围。     

在SO42-/ZrO2 上苯与丙烯的烷基化反应

Super acidic catalyst SO42-/ZrO2 was prepared and characterized by XRD,IR,and Py-IR. Selectively catalytic gas phase flow reactions of benzene and propene over the catalyst were carried out in a made-to-measure high pressure flow reactor with a thermometer and a condenser. The benzene and propene were kept in pressure tanks at 8 : 1 ratio with N2 gas at 4. 0 MPa. The reactants were pumped into the quantifier where the pressure was maintained by N2 gas at 8. 0 MPa. They were then pumped into the reaction reactor using catalytic synthesis of isopropyl benzene. The collected liquid phase products were analyzed using GC-MS. Product analyses were carried out on SE-54. The effect of the preparative condition on the catalytic synthesis of isopropyl benzene over the catalysts has been tested. The result shows that the SO42-/ZrO2 can be used as a catalyst for the title reaction,and shows higher conversion（99.2%）for the propene and higher selectivity（93.3%）for the isopropyl benzene when the catalyst is preparated in some condition.     

纳秒强激光电离苯产生高价碳离子的波长效应

The photoionization of seeded benzene beam by 25 ns laser pulse at wavelengths of 266,355 and 1064 nm has been studied by the time-of-flight mass spectrometry. The observed mass spectra at 266 nm and 355 nm at intensities of 1010-1011 W/cm2 indicate a multiphoton ionization and dissociation（MPID）process,in which C+,C2Hx+,C3Hx+,C4Hx+ and C6H6+ are main products. While at 1064 nm laser of similar intensities,the domain ion is C4+ which is produced from Coulomb explosion. The longer wavelength facilities the energy absorption rate during inverse bremsstrahlung,which leads to the resulting wavelength dependence of the multicharged atomic ions.     

Synthesis of Phenolic Compounds via Palladium Catalyzed C−H Functionalization of Arenes

Phenol and its derivatives are extremely useful compounds in organic synthesis, medicinal chemistry and material sciences. The synthesis of phenols involving selective construction of the C?O bond at a C?H bond of arenes using transition‐metal catalysis represents the most appealing strategy. Indeed, active research is currently going on for the synthesis of valuable phenolic compounds using a transition‐metal‐catalyzed C?H functionalization strategy. This short review summarizes recent advances on palladium‐catalyzed C?O bond forming reactions that enable direct access to phenolic compounds. These catalytic reactions proceed either via C?H esterification with trifluoroacetic acid/trifluoroacetic anhydride followed by in situ hydrolysis of the ester or via direct C?H hydroxylation. A brief analysis of substrate scope and limitation, reaction mechanism as well as synthetic utility of these reactions has been included.     

Adsorption of benzene from benzene/n-C6 and n-C7 mixture by nano Beta zeolite with different Si/Al ratios

The adsorption of benzene from benzene/n-alkane mixtures was studied by two types of nano Beta zeolite with Si/Al ratios of 11.5 and 24.5. Benzene was adsorbed into benzene/n-hexane and n-heptane mixtures which had 0.5% up to 10% mole fraction of benzene using batch technique in the ambient temperature. The nano Beta zeolite has active sites on its surface, which have interaction with π electron in benzene, and this can increase the heat of adsorption. The Si/Al ratio defines the number of active sites in the zeolite surface and the heat of adsorption. However, an increase in the active sites of Beta zeolite declines the entropy of adsorption. Therefore, free energy of mixing specifies the potential of adsorption in Beta zeolite.As the results indicated in all mixtures, benzene is adsorbed more than n-hexane and n-heptane into the Beta zeolite surface, which suggests that this type of zeolite has a high separation factor (∼50) for benzene in Beta zeolite (Si/Al = 24.5). Also, Beta zeolite with Si/Al = 24.5 had a greater separation factor than Beta zeolite with Si/Al = 11.5 in similar mixtures.     

海洋真菌对苯和甲苯的降解诱导黄烷酮的羟基化转化

真菌在各种氧化酶的作用下能将苯环类化合物转化降解,但转化降解过程中诱发的高活性酶的应用仍未见报道。本文研究海洋真菌Pseudallescheria boydii和Trichoderma erinaceum在添加苯和甲苯的培养条件下,诱导黄烷酮向4'-羟基黄烷酮的转化。结果表明,2种真菌对苯和甲苯有强耐受力,其降解过程中诱导的氧化酶对黄烷酮的羟基化具有高度的区域选择性,即发生4'-羟基化反应,而且转化率最高可达到82%,在酶促进的反应领域具有潜在的应用价值。     

Benzene formation in premixed fuel-rich 1,3-butadiene flames

Detailed kinetic modeling and flame-sampling molecular-beam time-of-flight mass spectrometry are combined to unravel important pathways leading to the formation of benzene in a premixed laminar low-pressure 1,3-butadiene flame. The chemical kinetic model developed is compared with new experimental results obtained for a rich (? = 1.8) 1,3-butadiene/O₂/Ar flame at 30 Torr and with flame data for a similar but richer (? = 2.4) flame reported by Cole et al. [Combust. Flame 56 (1) (1984) 51-70]. The newer experiment utilizes photoionization by tunable vacuum-ultraviolet synchrotron radiation, which allows for the identification and separation of combustion species by their characteristic ionization energies. Predictions of mole fractions as a function of distance from the burner of major combustion intermediates and products are in overall satisfactory agreement with experimentally observed profiles. The accurate predictions of the propargyl radical and benzene mole fractions permit an assessment of potential benzene formation pathways. The results indicate that C₆H₆ is formed mainly by the C₃H₃ + C₃H₃ and i-C₄H₅ + C₂H₂ reactions, which are roughly of equal importance. Smaller contributions arise from C₃H₃ + C₃H₅. However, given the experimental and modeling uncertainties, other pathways cannot be ruled out.     

换热器的综合效率分析

利用分析的方法对换热器进行了性能分析,推导出了综合评价换热器性能的公式;并以芳烃生产工艺中制苯工段的换热器为实例进行了具体的效率分析,得出了换热器的效率、单位面积的收益、损失及综合性能评价指标。结果表明:流体发生相变的换热器的性能要优于单相流体换热器的性能。