钛硅分子筛TS-1催化氯丙烯环氧化反应动力学研究

 摘要：研究了钛硅分子筛催化氯丙烯环氧化反应的条件及动力学行为．\r\n结果表明，以钛硅分子筛为催化剂，氯丙烯可被高选择性地氧化为环氧\r\n氯丙烷．环氧化反应速度与分子筛中骨架钛的含量及分子筛的用量呈正\r\n比关系，是一级反应．对于氧化剂H2O2，只有当c（H2O2）＜0．4mol／\r\nL时，环氧化反应为一级反应；而c（H2O2）＞1．0mol／L时，为零级反\r\n应．对于氯丙烯，随着其浓度的变化，环氧化反应的级数在1和0之间．\r\n然而，只有当氯丙烯浓度很高时，环氧化反应的级数才有明显的降低．\r\n根据实验结果和Eley－Rideal单分子吸附方程，提出了氯丙烯环氧化反\r\n应的动力学模型．\r\n关键词：钛硅分子筛，氯丙烯，过氧化氢，环氧化，环氧氯丙烷，反应\r\n动力学     

以TiCl4为钛源合成钛硅分子筛

Since titanium silicalite-1 (TS-1) was first prepared by Taramasso et al[1] in 1983,the synthesis of TS-1 and its application in partial oxidation have become a hotspot in the zeolite catalytic field.For the traditional synthesis route of TS-1,the key problem is its costly price and severe synthesis conditions,which hamper its industrial application.To avoid using costly alkali-free tetrapropylammonium hydroxide (TPAOH) as a template,Müller et al[2] reported that TS-1 could be synthesized using tetrapropylammonium bromide (TPABr) as a template with ammonia as the base to adjust the basicity of the gel.     

添加吐温40合成钛硅分子筛TS-1

 以自制的四丙基氢氧化铵（TPAOH）水溶液为模板剂，采用在水热晶化合成体系中添加少量非离子表面活性剂——吐温40的方法,合成了钛硅分子筛TS-1，可以明显减少TPAOH的用量，而且在一天之内，即可得到纳米尺寸的TS-1。运用XRD、TEM、BET、FT-IR及UV-Vis等表征手段考察了TS-1的结构及物理性能，并以丙烯环氧化为探针反应，考察其催化性能，得到的结果表明，用这种方法合成的TS-1样品具有较高的结晶度和较大的比表面积，晶貌呈均匀的立方体状，颗粒尺寸在100 nm左右，并且样品中含有极少量锐钛矿型TiO2，其催化丙烯环氧化反应性能较好。     

用不同方法合成的钛硅分子筛TS-1的拉曼光谱研究

采用不同方法合成了钛硅分子筛ＴＳ－１,Ｒａｍａｎ光谱表征表明,不同方法合成的ＴＳ－１分子筛中钛的分散状态不同,当钛的含量低于１．５％,不同方法合成的ＴＳ－１中的钛主要以高分散状态存在,当钛含量达到２．０％以上时,不同方法合成的钛硅分子筛中钛的分散状态显著不同,其中以ＴｉＣｌ３合成的分子筛中骨架钛的含最高,而杂晶相锐钛矿含量最低,同时催化氯丙烯环氧化活性也最高,而以正钛酸四丁酯为钛源,在静止态下晶化的钛硅分子筛中锐钛矿含量最高,催化活性最低。     

TPABr-TEAOH体系中TS-1的合成、表征及催化性能

ＴＰＡＢｒＴＥＡＯＨ体系中ＴＳ１的合成、表征及催化性能李钢郭新闻王祥生（大连理工大学碳资源综合利用开放研究实验室，大连１１６０１２）赵琦包信和韩秀文林励吾（中国科学院大连化学物理研究所，大连１１６０２３）关键词四丙基溴化铵，四乙基氢氧化铵，ＴＳ...     

以TiCl4醇溶液作钛源在水热体系中合成钛硅分子筛TS-1

钛硅分子筛ＴＳ－１的制备研究是催化领域的一个热点,采用异丙醇为溶剂调节ＴｉＣｌ４的水解活性,并对其为钛源在ＴＰＡＢｒ（四丙基溴化铵）－ＮＨ４ＯＨ体系中合成出了晶粒尺寸为３＊２μｍ的钛硅分子筛ＴＳ－１,用ＸＲＤ、ＩＲ、ＵＶ－Ｖｉｓ、ＳＥＭ等手段对所制备的样品进行了表征。通过对不同溶剂所起的作用的对比,发现醇溶剂分子的体积对钛硅分子筛的合成及着重要影响,其中异丙醇的使用能够有效的降低ＴｉＣｌ４的水解活性,使其与硅源的性质相匹配并促进沸石骨架上钛原子的引入;制得的分子筛ＴＳ－１在丙烯与过氧化氢的环氧化反应中表现出优异的催化性能。     

钛硅催化材料的研究进展 Ⅱ.钛硅分子筛TS-1的制备及其物化性能的研究

钛硅分子筛TS21由于其优异的催化氧化性能而受到极大关注。TS21的制备及基础研究是催化领域的一个热点。本文综述了近10年来钛硅分子筛TS21的制备研究进展, 讨论了在合成制备过程中模板剂、钛源、硅源、碱源、晶化条件等因素对钛硅分子筛TS21的影响, 并对其物化特点进行了评述。     

无机钛硅原料合成TS-1催化氯丙烯环氧化反应

采用无机钛硅原料体系合成出了TS-1分子筛,并对TS-1分子筛催化氯丙烯环氧化反应进行了研究.在以甲醇为溶剂的体系中考察了反应时间、反应温度、催化剂用量、氯丙烯与双氧水的摩尔比对反应的影响,得到了无机钛硅原料体系合成的TS-1催化氯丙烯环氧化反应的最优条件:反应时间为60 min,反应温度为45℃,催化剂用量为22.5 g L-1,氯丙烯与双氧水的摩尔比n(AC):n(H2O2)=1.8,并对无机钛硅原料体系合成的TS-1进行了修饰改性,评价了其催化性能.     

钛硅沸石中的一种非活性钛物种

Synthesis of the titanium silicalite TS-1 was first reported by Taramasso et al[1]in 1983. TS-1 has received considerable interest during the last decade because of its unique catalytic properties in oxidation reactions involving H2O2 as the oxidant. It is accepted that the extraframework Ti species in TS-1 favor the decomposition of H2O2and should be avoided. But in the present study, it was observed that there was a kind of Ti species inactive in both the oxidation reaction and the decomposition of H2O2.     

TS-2钛硅分子筛合成原料和方法的改进

以硅溶胶为硅源,钛酸四丁酯为钛源,四丁基氢氧化铵（ＴＢＡＯＨ）为模板剂,采用改进的方法合成了高结晶度的ＴＳ２分子筛,并对所合成样品用ＦＴＩＲ,ＸＲＤ,ＳＥＭ,２９ＳｉＭＡＳＮＭＲ,ＩＣＰ和Ｎ２吸附等方法进行了结构表征．实验中发现原料内添加适量氨水可使产品晶粒减小,骨架钛含量增加,比表面积和孔容增大,有利于提高其催化活性．另外,将晶化后母液中的ＴＢＡＯＨ循环使用,也能得到结晶度高和催化性能良好的ＴＳ２．采用本文推荐的合成原料和方法可大幅度降低ＴＳ２的合成成本     

A NOVEL METHOD FOR SYNTHESIS OF TS-1

Ｉｎｂｏｔｈｃｏｎｖｅｎｔｉｏｎａｌｍｅｔｈｏｄ［１］ａｎｄｍｏｄｉｆｉｅｄｍｅｔｈｏｄ［２］,ｏｒｇａｎｉｃＳｉａｎｄＴｉａｌｋｏｘｉｄｅｓｗｅｒｅｕｓｅｄａｓＳｉｓｏｕｒｃｅａｎｄＴｉｓｏｕｒｃｅｒｅｓｐｅｃｔｉｖｅｌｙ,ａｎｄｏｎｌｙｓｔｒｏ...     

Novel method for synthesis of titanium silicalite-1 (TS-1)

Titanium silicalite-1 (TS-1) was easily synthesized using inorganic silicon and titanium source, tetrapropylammonium bromide (TPABr) or TPAOH as templating molecule, NH3· H2O, HDA or TEAOH etc. as base sources. In this system, TPA cations (come from TPABr or TPAOH) served as tern-plating agents to direct the MFI structure. NH3H2O, TEAOH or HDA etc. provides the alkalinity necessary for crystallization. X-ray diffraction, UV-Vis, ER spectroscopies, SEM, 29 Si MAS NMR showed that the zeolites obtained possessed all the structural characteristics of TS-1, and titanium atoms were introduced into the framework in TS-1. This material was proved to have high crystallinity and high catalytic activity to allyl chloride epoxidation and propylene epoxidation. All the samples synthesized had similar catalytic properties with a standard TS-1 through compared inorganic reactant system with organic synthesis system using propylene epoxidation. The effects of silicon source and TPABr/SiO2 ratio were discussed.     

Effect of solvents on propylene epoxidation over TS-1 catalyst

Solvents have an important effect on the epoxidation of propylene catalyzed by TS-1. The experimental results show that, in different solvents, the catalytic activity of epoxidation is in the following order: methanol > 2-propanol > 2-butanol > acetonitrile > acetone > tetrahydrofuran. Based on the reaction mechanism, the effects of solvents on the epoxidation were studied from eight aspects, which included the electronic effect, the steric effect, the polarity of solvent, the effect of solvent on sorption and diffusion of reactant, the oxidation of alcohol, the etherification of PO, the deactivation of TS-1 and the solubility of propylene in the solvents. The electronic effect, steric effect and the polarity of solvent were considered to be the main aspects. This work may provide theoretical guidance for choosing solvents for these kinds of reactions and also may serve as basis for further industrialization. __________ Translated from Journal of Tsinghua University (Science and Technology), 2007, 47(9): 116–120 [译自: 清华大学学报(自然科学版]     

不同TS-1分子筛含量条状催化剂的丙烯环氧化性能

环氧丙烷(PO)是重要的有机化工原料，主要用于生产聚醚多元醇、丙二醇及其它化工产品。现在工业上主要采用氯醇法和Halcon法生产环氧丙烷，但分别存在污染和联产物量大等问题，人们在改进原有工艺的同时，致力于寻找流程短、副产少、无污染的新工艺。TS-1分子筛的成功合成^[1]及其在以     

基于 H2/O2 等离子体和钛硅沸石的丙烯气相环氧化方法

 将 H₂/O₂ 非平衡等离子体现场产生的气态 H₂O₂和丙烯与耦合反应器中钛硅沸石 TS-1 直接接触, 实现了丙烯气相环氧化反应. 结果表明, 非平衡等离子体生成气态 H₂O₂ 的速率由介质阻挡放电的输入功率决定, 环氧丙烷的生成速率和选择性取决于钛硅沸石催化剂和反应条件. 在 H₂ 和 O₂ 进料流量分别为 170 和 8 ml/min, 介质阻挡放电输入功率为 3.5 W, 环氧化反应温度为 110 ^oC, 丙烯进料量为 18 ml/min, 催化剂用量为 0.8 g 的条件下, 生成环氧丙烷产率达 246.9 g/(kg•h)、环氧丙烷选择性和 H₂O₂ 有效利用率分别为 95.4% 和 36.1%, 反应 36 h 内未见催化剂失活.     

钛硅酸盐分子筛TS－1的合成及表征

钛硅酸盐分子筛ＴＳ－１的合成及表征马淑杰，李连生，刘国宗，林文勇（吉林大学化学系，长春１３００２３）苏克，李莹（长春地质学院测试中心，长春１３００２１）关键词ＴＳ－１沸石，合成，苯酚，催化氧化＊～ｓ－ＺＳＭ－５沸石是Ｓ！Ｉ。。１ｕｅ－１沸石的衍生物，...     

Influence of process parameters on the epoxidation of 2-buten-1-ol over titanium silicalite TS-1 catalyst

The influence of process parameters on the epoxidation of 2-buten-1-ol with 30 % hydrogen peroxide using the titanium silicalite TS-1 is presented. The studies were carried out under autogenic pressure (in autoclave). Methanol was used as a solvent in this process. The influence of temperature, 2-buten-1-ol to hydrogen peroxide mole ratio, amount of solvent used, TS-1 catalyst content, and reaction time on the reaction was studied. The major product of this reaction, 2,3-epoxybutan-1-ol (EB), has numerous applications in chemical industry.     

Titanium Defective Sites in TS-1: Structural Insights by Combining Spectroscopy and Simulation

Ti silicates, and in particular, titanium silicalite-1 (TS-1), are nowadays important catalysts for several partial oxidation reactions in the presence of aqueous H₂O₂ as an oxidant. Despite the numerous studies dealing with this material, some fundamental aspects are still unclear. In particular, the structure and the catalytic role of defective Ti sites, other than perfect tetrahedral sites recognized as the main active species, has not been quantitatively discussed in the literature. We assess the structural features of defective Ti sites on the basis of outcomes of electronic spectroscopies, as interpreted through quantum mechanical simulation. Strong evidence is disclosed to support the fact that the most common defective Ti sites, often reported in the TS-1 literature, are monomeric Ti centers that are embedded in the zeolite framework, and which have a distorted octahedral local symmetry.     

两段法甲烷催化氧化制合成气研究

提出了一种将甲烷低温催化燃烧和部分氧化相结合制取合成气的新方法 ,考察了反应条件对Pd Pt催化剂上的甲烷低温燃烧反应性能以及Ni-La2 O3 MgAl2 O4 -Al2 O3催化剂上甲烷催化氧化制合成气反应性能的影响。结果表明 :采用两个串联固定床反应器和分段进氧 ,不仅可以使反应原料偏离爆炸极限 ,确保过程的安全操作 ;而且一段反应器采用低温进料 ,通过少量甲烷催化燃烧 ,为二段反应提供含有少量CO2 、H2 O等氧化产物的反应原料。在二段反应器中 ,放热的甲烷部分氧化反应和吸热的蒸汽重整及CO2 重整反应同时进行 ,可避免催化剂床层飞温 ,使反应基本上在绝热恒温条件下进行 ,可用两个串联的固定床反应器实现甲烷部分氧化制合成气反应。在适合的反应条件下 ,甲烷转化率可达 93% ,H2 和CO选择性分别为 97%和 98%。     

Preparation of Magnetic TS-1 and Its Catalytic Activity

Magnetic TS-1 was synthesized with nanosized nickelferrite particles as nuclei via the hydrothermal synthesis and solvent vaporation method. The prepared samples were characterized with N₂ adsorption-desorption isotherms, FTIR spectrometry, Raman spectrometry, X-ray diffraction, Ultraviolet-visible spectroscopy and Vibrating sample magnetometry. The results show that the composite obtained was composed of TS-1 with MFI structure and NiFe₂O₄ with spinel structure, its specific surface area was about 316 m²/g, pore volume was 0.12 cm³/g and pore size distribution was in the range of 0.5-0.7 nm. The catalytic activity of the composite was also investigated by its catalyzing the decomposition of rhodamine B oxidized by H₂O₂ in aqueous solution. In this case Rhodamine B pollutant could be completely degraded within 150 min. Magnetic TS-1 exhibited high photocatalytic efficiency and super paramagnetic nature for cleaning polluted water with the help of magnetic separation.