新型两步法合成高质量Silicalite-1分子筛膜

通过一种新颖的两步合成方法,即先用改性剂溶液对镀有二氧化硅缓冲层的多孔氧化铝(孔径0.1～0.5μm)载体管进行浸泡处理,再水热合成,制备了silicalite-1分子筛膜,并考察了晶化温度、晶化时间对成膜的影响.采用溶胶-凝胶(sol-gel)法,在最优粘度5～25 cp内制得平整连续的介孔缓冲层,达到了修饰载体材料表面性能的目的.X射线衍射(XRD)和扫描电镜(SEM)结果表明,160℃下,晶化24 h得到表面致密、连续的6取向的silicalite-1分子筛膜.     

TS-1催化丁酮氨氧化制丁酮肟反应过程

在2 5 0mL不锈钢高压反应釜中,以TS 1分子筛为催化剂,丁酮、氨水和过氧化氢进行氨氧化合成丁酮肟。试验研究了溶剂、反应温度、氨酮比和过氧化氢加料方式对丁酮的转化率和丁酮肟的选择的影响。结果表明,氨和丁酮的摩尔比为2. 15 ,反应温度70℃,H2 O2 采用连续进料的条件下,反应的转化率和选择性分别达到99 .12 %和10 0 . 0 0 %。表明在温和条件下TS 1催化丁酮氨氧化制丁酮肟是可行的。     

高温下反胶束体系中Silicalite-1沸石的合成

对反胶束体系中Silicalite-1沸石的合成进行了研究,得到了不同形貌的沸石产品。考察了表面活性剂用量、硅源等参数对合成Silicalite-1沸石结晶度和形貌的影响。结果表明,在实验考察范围内,正庚烷用量、表面活性剂/四丙基氢氧化铵质量比及硅源对产品的结晶度和形貌影响较大,而NaOH用量对产品的影响不明显。通过调节合成参数,得到了球形、棺材状、六角状的Silicalite-1沸石。     

重量法测定对二甲苯在Silicalite-1上的吸附

采用重量法研究了温度为423 K、373 K、343 K和323 K时对二甲苯在Silicalite-1分子筛上的吸附和脱附行为。结果表明, 温度为323 K和343 K时吸附等温线出现了两个吸附平台。根据吸附等温线计算了热力学参数（吸附等容热、吉布斯自由能变、熵变和吸附相熵）。随着吸附量的增大,吸附等容热增大,吸附的吉布斯自由能变稍有下降,吸附熵变逐渐增大,吸附相的熵逐渐减小,分子间的相互作用逐渐增强。对吸附和脱附动力学进行了研究,发现在吸附量大约为4 m·(u.c.)^－1时,扩散系数出现了峰值。     

三相体系中TS-1分子筛催化环己酮氨肟化制环己酮肟(英文)

An innovative green process of producing ε-caprolactam was proposed by integrating ammoximation and Beckmann rearrangement effectively. As a first part of the new process, TS-1 molecular sieve-catalyzed synthesis of cyclohexanone oxime from cyclohexanone, ammonia and hydrogen peroxide was carried out in a batch plant. Cyclohexane was used as the solvent in the three-phase reaction system. The influences of essential process parameters on ammoximation were investigated. Under the reaction conditions as catalyst content of 2.5% (by mass); H 2 O 2 /yclohexanone molar ratio of 1.10; NH 3 /cyclohexanone molar ratio of 2.20; reaction temperature of 343 K; reaction time of 5 h, high conversion of cyclohexanone and selectivity to oxime (both>99%) were obtained. Thus, the three-phase ammoximation process showed equal catalytic activity as TS-1 but much more convenient and simpler for the separation of catalyst in comparison to the industrial two-phase system with t-butanol used as solvent.     

有机介质中合成二硫化钛

本文研究了硫化氢与四氯化钛在某些有机介质中的反应，并提出了一个合成二硫化钛的新方法。该法是将干燥的硫化氢通入沸腾的四氯化铁的α－氯代萘溶液中，使硫化氢和四氯化钛发生复分解反应而生成二硫化钛。方法简便易行。Ｘ－射线物相鉴定及化学分析结果表明，产物为单一物相的、符合化学计量的二硫化钛。     

有机钛化合物在不对称合成中的应用

综述了近年来有机钛化合物在不对称合成中的一些应用,阐述了有机钛化合物在不对称加成反应、不对称氧化反应、不对称硅氰化反应等方面的应用.     

钛化合物在有机合成中的应用

综述了近年来钛化合物在有机合成中的应用，包括氧化反应、还原反应、偶联反应等，其中着重介绍了钛化合物在有机不对称合成中的应用。     

纳米晶种涂层法合成Silicalite-1沸石膜

用纳米晶种涂层二次生长成膜法在大孔a-Al2O3(孔径4~6 mm)陶瓷管上合成Silicalite-1沸石膜. 用X射线衍射(XRD)和扫描电镜(SEM)表征分析了沸石膜的形态,并通过单组分气体渗透实验对合成膜管的渗透性能进行了测试. 结果表明,合成的Silicalite-1沸石膜连续、互生,看不出晶间孔;沸石膜层厚8~10 mm;常温常压下H2/N2的理想分离系数为3.9,超过其努森扩散值3.74,H2/C3H8的理想分离系数为19.1,远大于其Knudsen扩散比值4.69,且H2的渗透率达到1.43′10-6 mol/(m2×s×Pa). 气体分离数据表明,该膜没有明显的缺陷存在.     

Low-Temperature Synthesis of Nanocrystalline Titanium Nitride via a Benzene–Thermal Route

A benzene–thermal reaction of TiCl₄ and NaN₃ at 350°–380°C was conducted for the preparation of nanocrystalline TiN. Powder X-ray diffractometry patterns indicated that the powder was cubic-phase TiN with a lattice constant a = 4.23656 Å. Transmission electron microscopy images showed the TiN powders consisted of uniform spherical particles with an average diameter of 50 nm. The binding energies of Ti 2 p 3/2 and N 1 s core levels at the positions of 454.85 and 397.1 eV, respectively, and the Ti:N atomic ratio of 1.08:1.00 were detected by X-ray photoelectron spectra. A possible formation mechanism of TiN was proposed.     

低成本TS-1的制备及其在丙烯环氧化中的应用

综述了低成本钛硅分子筛TS-1的制备及其在丙烯环氧化反应中的应用研究进展。低成本TS-1制备过程实现工业化主要存在粉末状TS-1的回收和过氧化氢的生产、储存等问题。提高活性及进一步降低成本是研究的重点。过氧化氢的生产与丙烯环氧化过程的集成是未来的发展方向。     

Impurities in the Combustion Synthesis of Titanium Carbide

The evolution of solid and gaseous impuritics from powders and their effects during the combustion synthesis (self-propagating high-temperature synthesis) of titanium carbide have been studied. First, the volatiles from the precursor powders, released during bakeout in a vacuum furnace, were measured by residual gas analysis. Second, both condensable and non-condensable materials emitted during the reaction of the Ti + C system were analyzed. The results indicate that the major noncondensing species in both cases were water vapor, hydrogen, carbon monoxide, carbon dioxide, and hydrocarbons. Significant amounts of oxygen and TiO₂ were also enitted during the reaction, but were not observed during bakeout. These impurities are shown to affect not only the reaction process, but also the microstructure of the reaction product.     

Effect of Porosity on the Combustion Synthesis of Titanium Nitride

The effect of porosity on the self-propagating reaction between porous titanium and gaseous nitrogen was investigated. The relationship between total nitrogen uptake and porosity showed a maximum at about 44% porosity. High initial sample porosities lead to partial melting of the titanium and subsequently to a lower degree of conversion to the nitride. Low initial porosities limit the conversion through lower reaction interfacial areas and lower gas permeation. Wave velocity measurements, thermogravimetric determinations on the progression of the combustion front, and microstructural analyses demonstrated that the passage of the front is associated primarily with the formation of a surface layer of TiN_1-x with x being 0.10 and 0.06 for lowdensity (49%) and high-density (59%) samples. The product of combustion contained titanium nitride and primary and β-transformed α solid solutions. The relative abundance of the latter two phases was dependent on the initial relative density of the samples.     

真空晶种引入法制备Silicalite-1沸石膜及其性能表征

采用抽真空法在多孔a-Al2O3载体管表面预先引入Silicalite-1沸石晶种,再通过水热合成二次晶化法在涂有Silicalite-1沸石晶种的a-Al2O3载体管上合成沸石膜. 用X射线衍射(XRD)、扫描电镜(SEM)和透射电镜(TEM)对合成的沸石分子筛及膜进行了表征,考察了晶种大小、真空度对合成沸石膜渗透性能的影响,用单组分气体渗透实验检测合成沸石膜的渗透性能. XRD检测结果表明,制备的沸石膜是典型的Silicalite-1沸石膜,合成的分子筛粒径分别约为0.2, 0.5, 1和2 mm,且分布均匀;SEM检测结果表明引入的晶种涂层连续、均匀,制备的Silicalite-1沸石膜致密、互生,不存在裂缺;常温常压下,H2/N2和H2/SF6的理想分离系数分别达到4.1和133.2,大于其Knudsen扩散比值3.7和8.7.     

新型受体分子——糖番的合成研究进展

糖番是由醛糖化合物与芳香族化合物反应而生成的大环化合物,构象上与环糊精和环番间存在着相似和差异,兼有环糊精和环番的性质,可以看成是环糊精和环番的的复合体分子。是一种具有很高研究开发和应用价值的新型手性受体分子。就其最新合成研究进展作一综述。     

硫酸钛催化合成乙酸异戊酯的工艺研究

以硫酸钛为催化剂,乙酸与异戊醇为原料合成了乙酸异戊酯,分别讨论了酸醇物质的量比、催化剂用量、反应时间等因素对酯化率的影响。确定了最佳工艺条件为：以0．2mol乙醇为基准,酸醇物质的量比为1．5：2,催化剂用量为0．5g,反应时间为90min,乙酸异戊酯的酯化率为99．18％。该催化剂具有催化活性高、用量小、反应时间短、可连续使用多次、与目前工业中使用的硫酸相比污染小、对设备无腐蚀等优点,且硫酸钛来源广泛、性质稳定、不溶于反应体系,是一种很有发展前景的催化剂。     

在玻璃上合成有取向的silicalite-1分子筛膜及其生长机理

引言 分子筛膜具有规则的微孔结构、良好的化学和热稳定性,在气体分离、催化膜反应器、化学传感器以及分子筛改性电极等方面有广泛的应用前景[1-2],是催化和分离新材料领域的研究热点之一.     

1-甲酰基苯并三唑席夫碱的合成及荧光性能

以苯并三唑、甲醛、伯胺为原料,合成了3种新的1-甲酰基苯并三唑席夫碱,分别简称为FBTTS、FBTSC和FBTAP。其最佳反应条件是以TBAB为相转移催化剂,三氯甲烷作溶剂,反应温度控制在50~55℃。通过IR、元素分析等检测手段,确证了3种新席夫碱的相应结构,并对其荧光性能进行了初步测试。     

Effect of triethylamine treatment of titanium silicalite-1 on propylene epoxidation

Titanium silicalite-1(TS-1) treated with triethylamine (TEA) solution under different conditions was characterized by X-ray powder diffraction (XRD), Fourier-transform infrared spectrum (FTIR), ultraviolet-visible diffuse reflectance spectrum (UV-Vis), nitrogen physical adsorption and desorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The characterization results show that many irregular hollows are generated in the TS-1 crystals due to the random dissolution of framework silicon and the volume of the hollow cavities increase with increasing the TEA concentration, and the treatment temperature and time. The modified TS-1 samples improved in varying degrees the catalyst life for the epoxidation of propylene in a fixed-bed reactor probably due to the generation of the hollows to make it easy for the reactants and products to diffuse out of the channels.     

酸处理红辉沸石-碱-铝酸钠-水的水热反应体系中A型沸石的合成

以酸处理红辉沸石为原料,采用水热反应晶化合成工艺,合成出了质量较高的4A沸石产品,在大量实验基础上,利用X射线衍射分析,扫描电镜观察等系统地研究了反应混合物的钠硅比[n(Na2O)/n(SiO2)]和水钠比[n(H2O)/n(Na2O],以及晶化时间和晶化温度对酸处理红辉沸石－碱－铝酸钠－水的水热反应体系中A型沸石晶化合成的影响,确定了最佳工艺技术参数：硅铝化[n(SiO2)/n(aL2O3)]为2,钠硅比[n(Na2O)/n(SiO2)]为1,1,水钠比[n(H2O)/n(Na2O]45,晶化时间大于6h,晶化温度为100℃。