正己烷在某些金属改性ZSM_5上的芳构化反应

本文对Ｎｉ，Ｃｕ，Ｚｎ三种金属改性的ＺＳＭ－５上正己烷的芳构化反应进行了探讨和比较，发现这些金属的引入在促进正己烷的芳构化性能方面既有共同点，也有某些差异，同时还研究了催化性能和酸性的关系，并就Ｂ酸和Ｌ酸中心的协同效应对芳构化的促进作用提出了看法。     

纳米ZSM-5分子筛的液相沉积改性及其催化己烯-1芳构化反应性能

烯烃芳构化是催化裂化(FCC)汽油改质、高辛烷值燃料油的重要手段.采用预制晶种法合成了纳米ZSM-5分子筛,并采用液相沉积法制备了Ga沉积量不同的系列改性纳米ZSM-5分子筛,分别采用XRD、N2物理吸附、SEM、TEM、XPS、H2-TPR和Py-IR等表征手段对改性前后的纳米ZSM-5分子筛的形貌、织构特性和酸性等进行了表征,并采用固定床微型反应器对其催化己烯-1芳构化反应性能进行了评价,研究了Ga改性对纳米ZSM-5分子筛的物理化学性质及催化性能的影响规律.Ga液相沉积改性的ZSM-5分子筛中Ga物种主要以Ga2 O3和提供强Lewis酸性位的GaO+形式存在,由于Ga改性提高了分子筛的脱氢反应活性,己烯-1芳构化反应的芳烃选择性显著提高,以Ga沉积量适宜的Ga4.2/NZ5为催化剂时,芳烃选择性高达55.4％.     

ZSM-5分子筛的改性研究及其酸性表征

通过正交实验法,对ZSM-5分子筛进行金属锌改性研究,分别考察了分子筛硅铝比、金属锌含量、焙烧温度、焙烧时间对汽油裂解反应的综合影响,确定了最佳的改性条件,并对改性ZSM-5进行了红外酸性的表征.     

Fe( Ⅲ) - 改性ZSM- 5 催化剂酸性和积炭性能研究

本文用NH3 - TPD、吡啶- IR、GC 和微反色谱等技术考察了Fe ( Ⅲ) - ZSM- 5 催化剂在芳构化反应中的酸性、积炭行为以及催化性能的变化规律.结果表明, Fe ( Ⅲ) 修饰了沸石表面酸性, 减少了部分强B 酸中心, 加强了弱L 酸中心. 缓和了表面积炭和催化活性下降速率。并发现在反应初期, 强B 酸中心下降、积炭量的生成以及催化活性下降速度均较快.     

Zn/HZSM-5催化剂对乙烯芳构化反应影响

报道了Zn/HZSM-5催化剂对乙烯芳构化的反应影响,研究了载体Si/Al比、金属含量、反应温度等对催化剂催化性能的影响.通过XRD和TG-DTA对催化剂进行了表征,并对Zn负载的HZSM-5双功能催化剂在乙烯芳构化反应中的作用进行了简单的讨论.     

Fe（Ⅲ）—改性ZSM—5催化剂酸性和积炭性能研究

本文用NH3－TPD，吡啶－IR，GC和微反色谱等技术考察了Fe(Ⅲ）－ZSM－5催化剂在芳构化反应中的酸性，积炭行为以及催化性能的变化，结果表明，Fe(Ⅲ)修饰了沸石表面酸性，减少了部分强B酸中心，加强了弱L酸中心，缓和了表面积炭和催化活性下降速率，并发现在反应初期，强B酸中心下降，积炭量的生成以及催化活性下降速度均较快。     

低成本ZSM-5型沸石分子筛的合成及其吸附性能

以廉价的工业废弃物粉煤灰作为初始原料,四丙基氢氧化铵（TPAOH）为模板剂,分别采用两种合成方案制备出微孔分子筛ZSM-5样品。该法相较传统水热法,原料价廉易得,制备工艺简单。通过XRD、SEM、TR等手段对样品进行表征,发现两种方案均合成出了较高质量的ZSM-5,但形貌分别为薄片型和长六方体型。最后考察了其对水中Cr（Ⅵ）离子的吸附性能,结果表明合成的ZSM-5型样品对Cr（Ⅵ）离子有较好的吸附性能。     

二次孔分布对正己烷在5A分子筛颗粒上吸附扩散性能的影响

采用IGA - 100型智能重力分析仪测定在100 ～300℃,0.01 ～ 10 kPa下,5A分子筛对正己烷的吸附速率曲线,分析了不同二次孔分布的成型5A分子筛颗粒5A-1和5A-6对正己烷的吸附扩散性能.结果表明:5A-1与5A-6分子筛具有相近的微孔和中孔孔径分布;5A-6分子筛在孔径0.1～1 μm范围内拥有...     

低有机模板剂对合成ZSM-5沸石及其性能的影响

为在低有机模板剂的条件下合成形貌规则和结晶良好ZSM-5沸石提供策略.本研究以硅溶胶为硅源,偏铝酸钠为铝源,在四丙基溴化铵(TPABr)/SiO2(即模/硅比)为0.03～0.15范围内,采用水热合成法成功制备结晶良好和形貌规则ZSM-5沸石.利用XRD、SEM、N2吸附-脱附、NH3-TPD和ICP等手段对样品进行表...     

FeZSM-5沸石催化剂对联苯的催化硝化

主要研究沸石催化剂作用下联苯的选择性硝化反应.采用不同金属离子改性ZSM-5分子筛催化剂,制备出改性催化剂,通过研究不同的催化剂种类和用量,确定最佳的联苯硝化工艺条件.结果表明,以乙酸酐为溶剂,反应温度30℃、催化剂用量0.3g、硝酸/联苯的摩尔比为1.25∶1时,FeZSM-5沸石催化剂联苯的选择性硝化效果最佳,4-硝基联苯的选择性有了明显提高.     

Rapid synthesis of ZSM-5 zeolite catalyst for amination of ethanolamine

ZSM-5 zeolite was rapidly synthesized in system containing ethylenediamine from the initial gel: (5(8) Na2O: 44 EDA:Al2O3:100 SiO2:4000 H2O. The crystals were lath-shaped. The effect of pretreatment and alkalinity on crystallinity was investigated. The pretreatment of silicate source can cut down the crystallization time. Tuning the system alkalinity and controlling crystallization time can ensure forming of pure crystal.     

Rapid synthesis of ZSM-5 zeolite catalyst for amination of ethanolamine

INTRODUCTION ZSM-5 zeolite is a typical high silica zeolitewith MFI-type structure which makes ZSM-5 zeo-lite widely useful as catalysts in petroleum andpetrochemical industry. In recent years, the appli-cation of ZSM-5 is expanding into the synthesisfields of specialty and fine chemicals (Davis, 1998),such as the preparation of ethylene amines. The ex-cellent catalytic performance of ZSM-5 was noted(Hua and Hu, 2001). In most cases, the synthesis of ZSM-5 is ach-ieved…     

Synthesis and characterization of magnetic ZSM-5 zeolite

In order to separate ZSM-5 zeolite powders from solution easily, a series of magnetic ZSM-5 zeolites were prepared by hydrothermal synthesis with the addition of magnetic Fe3O4 panicles during the crystalline process. The products were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, infrared （IR） spectrum, energy dispersive X-ray （EDX）, specific surface area, magnetic susceptibility and adsorption capability. It was found that the magnetic ZSM-5 zeolites had good magnetism and the magnetic susceptibility increased with the increasing amount of Fe3O4 panicles. Compared with the pure ZSM-5 zeolite, the adsorption capability of magnetic ZSM-5 zeolites was acceptable. When the magnetic zeolites were used to adsorb Pb^2＋ from solution, the magnetic zeolite powder could be conveniently separated with magnetic separation technology.     

M-ZSM-5分子筛的结构及催化性能研究进展

探究了ZSM-5分子筛的晶体结构、孔结构及酸性质：对通过离子变换对其表面进行优化以提高催化活性方面的研究工作进行了阐述；对Cu-ZSM-5分子筛上NO直接催化分解反应提出了：4CuO=2Cu20＋02，2Cu2O＋4NO=4CuO＋2N2＋O2的反应机理。     

合成吡啶催化剂的研究

醛(酮)氨法合成吡啶可用ZSM-5作催化剂, 本文研究了ZSM-5催化剂的表面酸性与催化合成吡啶活性之间的关系. 合成了硅铝质量比为120的ZSM-5, 并用钴、铁对其进行改性, 用吡啶红外光谱技术测定了ZSM-5的表面酸性. 研究表明用Co2 ,Fe3 离子对HZSM-5进行改性, Lewis酸中心明显减少, 对氨的吸附能力下降, 这种现象保证了足够多的酸中心暴露和醛反应, 有利于吡啶碱的形成, 吡啶碱产率可达78%. 该研究为制备高活性、高选择性的合成吡啶催化剂提供了理论依据.     

Effects of acidity and mesoporosity development in ZSM-5 on biomass-derived ethylene oligomerization for liquid fuel synthesis

The acidities of different SiO2/Al2O3 ratio ZSM-5 zeolites, CBV3024E, CBV5524G and CBV8014 were investigated with temperature-programmed desorption of ammonia and diffuse reflectance infrared Fourier transform spectroscopy, and their catalytic performances were evaluated to screen the optimal CBV8014 catalyst for ethylene oligomerization. The mesoporosity development in CBV8014 zeolite was conducted by desilication in alkaline medium. The porous characteristics, structural properties and acidic properties of parent and alkali-treated CBV8014 zeolites were studied, and their catalytic performances were evaluated, indicating that CBV8014 treated by 0.2 mol/L NaOH solution has an appropriate mesoporosity development, well preservation of catalyst acidity and crystallinity, good catalytic activity and stability, and high liquid fuel yield for ethylene oligomerization. The effect of reaction pressure on ethylene oligomerization over 0.2HZ catalyst was also investigated, and JP-8 likely hydrocarbon jet fuel was obtained by using 0.2HZ catalyst at 0.344 75 MPa with a high catalyst stability and high liquid yield.     

High Pressure Vapor-Liquid Equilibrium of Supercritical Carbon Dioxide ＋ n-Hexane System

Vapor-liquid equilibrium data are important forthe design, development, and operation of supercriti-cal fluid separation processes[1].The main method forobtaining phase equilibrium data is experimentation.Most published articles on high-pressure fluid-phaseequilibrium experimental methods focus on supercriti-cal (SC) carbon dioxide because of its low criticaltemperature and pressure, nontoxicity, and lowcost. A feature of SC fluids is that their densities anddensity-dependentproperties are s…     

ZSM-12分子筛的合成研究

采用六亚甲基亚胺作为模板剂,通过动态水热晶化法成功合成了ZSM-12分子筛,考察了动态条件下各种因素对ZSM-12分子筛合成的影响.结果显示,提高温度、碱度、模板剂浓度以及延长反应时间有利于ZSM-12分子筛的合成.