杂多酸催化油酸甲酯环氧化的研究

研究了以磷钨酸-D1821(磷钨酸双十八烷基季铵盐)作催化剂,二氯甲烷作溶剂,30%过氧化氢存在下油酸甲酯的环氧化反应,考察了反应条件对油酸甲酯环氧反应的影响,得到的优化反应条件为:m(30%过氧化氢)∶m(油酸甲酯)=1∶1,m(二氯甲烷)∶m(油酸甲酯)=1.5∶1,m(催化剂)∶m(油酸甲酯)=25‰。在最优条件下得到的环氧油酸甲酯的碘值在4.3 g I2/100 g左右,环氧值在3.95 g/100 g左右,酸值在0.2 mg KOH/g左右,均达到了一等品的要求。     

环氧油酸甲酯合成工艺的研究

研究了以Keggin型磷钨酸季铵盐作催化剂,二氯乙烷作溶剂,30%过氧化氢存在下油酸甲酯的环氧化反应,考察了不同碳链的磷钨酸季铵盐对油酸甲酯环氧化的催化效果。结果表明,磷钨酸-D1821(磷钨酸双十八烷基季铵盐)的催化效果最好。以磷钨酸-D1821作催化剂,油酸甲酯环氧化反应的最佳反应条件为:m(30%过氧化氢)∶m(油酸甲酯)=1.5∶1,m(二氯乙烷)∶m(油酸甲酯)=3∶1,m(催化剂)∶m(油酸甲酯)=0.025∶1,反应温度50℃。在此条件下,得到的产品的碘价为2.64 g I2/100 g,环氧值为3.91 g/100 g,酸值为0.41 mg KOH/g,达到了一等品的要求。     

丙烯环氧化生成环氧丙烷催化剂（TS-1分子筛）的合成与表征

介绍了丙烯环氧化生成环氧丙烷催化剂(TS-1分子筛)的合成方法。着重对钛是否进入分子筛骨架的表征方法X射线粉末衍射、紫外漫反射、傅立叶红外、拉曼、程序升温脱附等技术进行了综述，对TS-1分子筛用晶形晶貌以及比表面积等也作了简要的介绍。并指出TS-1分子筛工业化前景乐观。     

DBU催化合成油酸甲酯及其机理初探

以1,8-二氮杂二环十一碳-7-烯(DBU)为催化剂,通过甲醇和油酸酯化反应合成了油酸甲酯。考察了n(甲醇)∶n(油酸)、DBU用量、反应时间等因素对油酸转化率的影响,并采用电导法对DBU催化甲醇和油酸反应的机理进行了研究。研究结果表明,当反应温度为60℃、n(甲醇)∶n(油酸)为6∶1、DBU用量为原料总质量的30%、反应时间为3h,油酸的酯化率为93.7%。甲醇+DBU溶液的电导率随DBU的加入呈现先上升、后下降的趋势,表明DBU的加入有助于甲醇失去活泼质子氢形成甲氧基负离子,从而促使酯化反应的进行。     

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。     

磷钨酸铋催化合成油酸甲酯

以磷钨酸铋为催化剂,对油酸和甲醇反应合成油酸甲酯进行了研究,考察了反应时间、催化剂用量、醇酸摩尔比、催化剂重复使用性等因素对油酸甲酯收率的影响.实验结果表明反应的最佳条件为:油酸用量为0.1 mol,醇酸摩尔比为1.4,催化剂磷钨酸铋用量为1.5 g,反应时间为4h,酯收率达93.4％,催化剂重复使用五次催化性能未见明...     

变温陈化法制备TS-1分子筛及其催化性能

通过变温陈化步骤,采用水热结晶法制备TS-1分子筛。改变陈化步骤,得到一系列粒径不同的TS-1分子筛,并探究粒径对丙烯醇环氧化反应催化性能的影响。采用FT-IR、UV-Vis、BET、XRD和SEM等表征TS-1分子筛催化剂晶相,结果表明,不同条件制得的TS-1分子筛具有相同的MFI结构,Ti大部分以骨架钛形式存在,也有少量锐钛矿相Ti O2存在。随着反应温度的升高,TS-1粒径逐渐增大。通过后续催化反应发现,TS-1分子筛催化剂的催化活性改变不大,这可能是由于催化剂中活性位点的数目变化不大。从催化剂分离实验可以看出,随着粒径的增大,催化剂回收率从82.4%增至95.3%。     

不饱和脂肪酸甲酯的绿色催化环氧化研究

选用氧化钼/叔丁基过氧化氢/阴离子离子液体{MoO3/TBHP/[bmimPF6]}(I)和氧化钼/过氧化氢/阴离子离子液体{MoO3/H2O2/[bmimBF4]}(II)两种绿色催化体系,探索了反应时间、反应温度、氧化剂/不饱和双键摩尔比和催化剂/不饱和双键摩尔比4个因素对不饱和脂肪酸甲酯环氧化转化率的影响。研究表明,实验条件下催化体系Ⅰ比催化体系Ⅱ具有更高的活性,MoO3可重复使用3次。     

钛硅分子筛催化合成1,2-环氧丁烷

研究了以TS 1钛硅分子筛作催化剂 ,以 30 %H2 O2 为氧化剂 ,1 丁烯催化环氧化反应。使用均匀设计方法详细考察了H2 O2 用量、催化剂用量、反应温度、反应时间等因素对反应的影响。得到了H2 O2 的转化率和 1,2 环氧丁烷的选择性与以上因素的回归公式 ,并通过实验对其进行了验证。     

两种体系合成的TS-1分子筛表征及其丙烯直接环氧化反应性能比较

采用SEM、XRD、微结构分析、IR等对以络合剂提高钛源稳定性体系和以传统体系合成的两种TS-1分子筛样品进行对比测试,并在高的双氧水浓度下考察了丙烯直接环氧化反应效果。结果表明,两种体系合成的TS-1分子筛样品的骨架结构、晶形、比表面积、孔径分布等基本一致,对丙烯直接环氧化的催化性能基本相当,但传统法合成的晶粒大小不一,而以络合剂提高钛源稳定性体系合成的晶粒为均一的均匀薄片状结构。这为较价廉体系合成TS-1分子筛的进一步研究、放大与工业应用提供了可能。     

纳米TS-1分子筛的合成及环己酮肟化反应性能

采用预晶化后补充硅源的合成方法,在模硅物质的量比0.15条件下,合成晶粒尺寸300 nm的TS-1分子筛。考察模板剂用量和预晶化时间对分子筛合成的影响,并采用XRD、SEM、TEM、UV-vis和N2吸附-脱附对分子筛进行表征,通过环己酮肟化反应考察分子筛催化性能。结果表明,相对于传统法合成的TS-1分子筛,采用预晶化补硅法合成的TS-1分子筛具有较大的比表面积和介孔体积,而且其非骨架钛含量减少,能够有效地提高环己酮肟化反应的转化率、选择性和催化剂寿命。     

Synthesis,characterization of hierarchical TS-1 and its catalytic performance for cyclohexanone ammoximation

A hierarchical titanium silicate (TS-1) that possesses large open voids has been prepared by using a dissolution/re-crystallization process. Carbon black was introduced as a hard template during the synthesis process to generate defects both inside and on the surface of crystals, then TPAOH post-treatment was applied, as a result, a novel TS-1 zeolite crystal with large open voids was successfully synthesized. The synthesized hierarchical TS-1 was characterized by XRD, FTIR, SEM, TEM and N₂ physisorption. Compared with the traditional TS-1 and hollow TS-1, the activity of hierarchical TS-1 in cyclohexanone ammoximation was improved and attributed to the macropores that linked the voids inside the zeolite directly to the outer surface.     

多级孔道纳米尺度TS-1的制备及性能评价

以四丙基溴化铵（TPABr）为模板剂、正丁胺（NBA）为碱源、可溶性淀粉作为硬模板空间填充剂,利用添加晶种且蒸汽辅助晶化的方式,制备出富含四配位Ti物种且具有多级孔道的纳米尺度TS-1,采用X射线衍射、紫外漫反射可见光谱、傅里叶变换红外光谱、电感耦合等离子光谱、N₂物理吸附-脱附及固体核磁共振等手段对所制备的样品进行一系列表征,并考察其对氯丙烯（ALC）环氧化反应的催化性能。结果表明,采用晶种辅助的方式晶粒尺寸可减小至280nm×170nm×500nm,淀粉的加入可制备出多级孔道结构且有效抑制非骨架Ti的产生;对于ALC的环氧化反应,当淀粉的添加量与SiO₂的质量比为0.4时,所制备的多级孔道TS-1催化活性最高,H₂O₂的转化率达到99.15%,环氧氯丙烷（ECH）的选择性为97.23%,并且此时ECH的收率及H₂O₂的有效利用率均较高。     

Efficient catalytic epoxidation of olefins with hierarchical mesoporous TS-1 using TBHP as an oxidant

A series of hierarchical mesoporous TS-1 zeolites with MFI structure were successfully synthesized via hydrothermal route using amphiphilic organosilanes as pore directing templates. These materials were characterized by nitrogen sorption (for surface area, pore volume and pore size distribution), FTIR, SEM and UV–Visible spectroscopy. These materials are efficient catalysts for liquid phase epoxidation of olefins using TBHP as the oxidant. All these TS-1 samples oxidized cyclohexene selectively into epoxide. For the TS-1 sample with 4.4 % Ti complete conversion of cyclohexene into epoxide was observed.     

Deuterium-hydrogen exchange during the catalytic deuteration of methyl oleate

Extensive exchange of deuterium for carbonbonded hydrogen takes place during the catalytic reduction of methyl oleate with gaseous deuterium. Mass spectrometric analysis of the deuterated stearate shows that it is composed as follows: a small part of one molecular species contains no deuterium; the largest contains 1 atom of deuterium; nearly as much contains 2 atoms; and progressively smaller numbers of molecules contain 3,4,5, and up to 11 atoms of deuterium per molecule. No appreciable exchange occurred with the hydrogen of methyl stearate in the presence of active palladium catalyst and deuterium. Methyl oleate, containing up to 9 atoms of deuterium in one species and 11/2 moles of deuterium average per mole, has been separated from the partially deuterated ester. This octadecenoate has 60–65% of its double bonds intrans configuration and only 18% of its double bonds in the original 9,10-position. Presented at AOCS meeting in Toronto, Canada, 1962. A laboratory of the No. Utiliz. Res. & Dev. Div., ARS, U.S.D.A.     

Nitrogen-incorporated TS-1 zeolite: Synthesis, characterization and application in the epoxidation of propylene

A novel nitrogen-incorporated TS-1 zeolite (N-TS-1) was successfully synthesized by direct calcinating the as-synthesized TS-1 powder in NH₃ flow at high temperature. The samples were characterized by XRD, FTIR, UV-Vis, NH₃-TPD, ICP-AES, CHN, XPS and ²⁹Si MAS NMR techniques. The results showed that nitrogen was incorporated into the framework of TS-1, and N-TS-1 preserved the MFI structure well. The fresh N-TS-1 samples showed low H₂O₂ conversion in the epoxidation of propylene with dilute H₂O₂, which was due to the coverage of the active titanium sites by unstable nitrogen species. By refluxing the fresh N-TS-1 samples with methanol, the unstable nitrogen species were washed out and the conversion of H₂O₂ increased markedly. The stable nitrogen species incorporated into the zeolite framework could effectively decrease the acidity of TS-1 zeolite and inhibit the side reactions, thereby improving the propylene oxide (PO) selectivity. After the 20th run, the N-TS-1-850-5 catalyst gave a H₂O₂ conversion of 91.5%, a H₂O₂ selectivity of 92.0%, and a PO selectivity of 90.9%. Finally, a model for nitridation of the as-synthesized TS-1 powder at high temperature was proposed.     

钛硅分子筛TS-1的合成改性及其催化功能

钛硅分子筛TS-1由于其优异的催化氧化性能而受到极大关注,TS-1的制备及基础研究是催化领域的一个热点。本文重点综述了近年来钛硅分子筛催化材料的合成、改性及其催化应用的研究进展,包括钛硅分子筛(TS-1)的水热合成方法和同晶取代合成法、改性、成型与负载以及钛硅分子筛催化氧化功能和酸催化功能的研究。