新型NU-85分子筛的物性表征与合成时间优化

首次采用预置晶种法,以溴化六甲双铵(HMBr_2)为模板剂,(160～180)℃合成分子筛NU-85。采用XRD、SEM及FT-IR等表征手段对样品物性进行表征。结果表明,该合成样品NU-85分子筛为EU-1和NU-87共晶生长,具有典型的EU-1分子筛和NU-87分子筛的特征衍射峰,结晶度较高。SEM照片显示,合成NU-85分子筛形貌为较规整长方体的堆积层叠物,聚集现象较常见。实验考察NU-85分子筛的二甲苯异构化催化性能,发现产物具有较高的二甲苯异构化反应活性和选择性。     

预置晶种合成EU一1/MOR复合分子筛

首次以溴化六甲双铵(HMBr2)为模板剂、丝光沸石(MOR)为晶种,采用预置晶种法在高浓体系中合成复合分子筛EU-1/MOR.在选定条件下,合适的MOR质量分数≥20%,30≤n(SiO2):n(Al2O3)≤60,晶化时间36 h≤T≤96 h,温度(420～450)K,合成出EU-1/MOR复合分子筛,且结晶度较好.采用XRD、SEM和IR等表征手段对样品进行分析,结果表明,合成出高纯度、高结晶度和具有优良催化性能的EU-1/MOR沸石.     

预置晶种合成EU-1／MOR复合分子筛

首次以溴化六甲双铵（HMBr₂）为模板剂、丝光沸石(MOR)为晶种，采用预置晶种法在高浓体系中合成复合分子筛EU-1/MOR。在选定条件下，合适的MOR质量分数≥20%，30≤n(SiO₂)∶n(Al₂O₃)≤60，晶化时间36 h≤T≤96 h，温度（420～450） K，合成出EU-1/MOR复合分子筛，且结晶度较好。采用XRD、SEM和IR等表征手段对样品进行分析，结果表明，合成出高纯度、高结晶度和具有优良催化性能的EU-1/MOR沸石。     

超细分子筛的合成和应用

综述了近年来超细沸石分子筛的合成方面的进展，并简介超细分子筛材料在催化领域中的应用。     

含NES型分子筛的研究进展

介绍了NES型分子筛的特点,综述了含NES型的NU-87、NU-85及ERS-10分子筛的研究进展,重点评述了其合成方法与催化应用,并对含NES型分子筛的研究前景进行了展望.     

MOR/EU-1复合分子筛的合成与表征

首次以TEABr为模板剂,EU-1为铝源,水热晶化合成复合分子筛MOR/EU-1.在合适的EU-1晶种添加量(m(EU-1)/m(SiO2)≤2)、模板剂添加量0.25≤n(TEABr)/n(SiO2)≤0.4,碱量1.16≤n(NaOH)/n(SiO2)≤1.71以及合适的晶化时间(48～96h)和晶化温度(140～...     

新型复合分子筛L/ZSM-5的合成与表征

在一定的SiO₂与Al₂O₃物质的量比和pH条件下,采用水热晶化法合成了L/ZSM-5新型复合分子筛。并通过X射线衍射（XRD）、扫描电镜（SEM）和红外光谱（IR）对样品进行了表征。讨论了酸量对合成的影响。结果表明,优化的加酸量为(0.802 0～0.939 9) g,在一定的酸性范围,酸性越强越有利于ZSM-5的生成,合成出的复合分子筛中ZSM-5所占的比率越高。     

晶种法合成TS-1分子筛催化剂

以价廉易得的四丙基溴化铵为模板剂,全硅分子筛凝胶为晶种,氨水为碱源合成TS-1分子筛,考察晶化时间和晶种添加量对骨架Ti含量的影响,并运用XRD、FT-IR和UV-Vis对合成的样品进行表征。结果表明,晶种的加入可有效促进Ti进入分子筛骨架,加快晶核的形成和晶体的生长,缩短晶化时间,降低合成成本。     

不同形貌ZSM-5分子筛的合成优化与表征

在考察采用不同模板剂合成结晶度较高ZSM-5分子筛的基础上,研究了大晶粒和不同形貌ZSM-5分子筛的控制条件.通过XRD表征产物的晶相结构,SEM观察产物分子筛的晶粒形貌,BET法测定分子筛的孔结构.制得的粒子为长方体和球形等,具有高结晶度和大外表面积.     

Cu-HMS分子筛的合成及其表征

以十二胺为模板剂、正硅酸乙酯为硅源，在中性介质中于25℃下合成了含Cu的中孔杂原子分子筛Cu—HMS。用XRD、FT—IR、UV—Vis、XPS、^29SiMAS NMR、低温N2吸附等手段对分子筛结构及表面性能进行了表征。结果表明，Cu进入分子筛的骨架结构并以Cu^2 的形式存在。在常压85℃下，以Cu—HMS为催化剂、纯O2为氧化剂，对异丙苯的催化氧化反应进行了研究，结果表明Cu—HMS是一种很好的洁净氧化催化剂。     

Shape selective conversion of 1,2,4-trimethylbenzene over zeolite NU-87

The catalytic properties of zeolite NU-87 were investigated in the conversion of 1,2,4-trimethylbenzene in view of the product selectivity. To examine the catalysis by external acid sites, experiments were conducted over NU-87 with external surface poisoned by 1,1,1,3,3,3-hexamethyldisilazane. For comparison, the results obtained over MCM-22, which has a similar pore structure, are also included. Both disproportionation (to xylene and tetramethylbenzene) and isomerization (to 1,2,3- and 1,3,5-isomers) take place over NU-87. Under the present conditions, it is found that the disproportionation proceeds largely within the micropores of NU-87, while the isomerization reaction occurs mainly on the external surface. The distribution of xylene isomers is thermodynamically controlled inside the pores, whereas amongst tetramethylbenzene isomers, the 1,2,4,5-isomer is selectively produced through the channel system. The bulky product, 1,2,3,5-tetramethylbenzene (or 1,3,5-trimethylbenzene), is severely hindered from diffusing through the channel system of NU-87. However, 1,2,3,4-tetramethylbenzene and 1,2,3-trimethylbenzene diffuse out of the micropores to a certain extent. In the case of MCM-22, the conversion of 1,2,4-trimethylbenzene hardly proceeds within the micropores. It is evident that NU-87 has larger pores and thus higher accessibility to 12-MR cavities than MCM-22.     

EU-1分子筛的催化裂化反应性能考察

分别以柴油和重油为原料,在微反活性评定和小型固定流化床装置上对EU-1、β及ZSM-5三种不同的分子筛催化剂的催化裂化反应性能进行了对比评价。结果表明,与基础剂相比,所掺EU-1助剂对产品分布改变不大,汽油辛烷值增加0.13;与等量ZSM-5助剂相比,EU-1助剂表现为液化气增量减少7.83%,总液收增高0.91%,但汽油辛烷值降低1.1;β分子筛对重油组分的裂化能力强于EU-1和ZSM-5,液化气增量介于EU-1和ZSM-5之间,具有一定增产丙烯和提高汽油辛烷值的能力。     

NaY沸石导向剂及其表征手段的研究进展

综述了NaY沸石的常规溶胶导向剂、高温长效溶胶导向剂、高铝溶胶导向剂、改性溶胶导向剂以及凝胶导向剂的性能和研究现状，并对其现有表征手段如分光光度计、UV拉曼、液相²⁹Si-NMR、液相²⁷Al-NMR、固相²³Na-NMR、电子衍射技术和硅钼黄动力学的特点进行了比较     

Modification and sequential treatment of EU-1 zeolite in mild alkali and alkaline-acid conditions

EU-1 zeolites were sequentially treated with low-concentration sodium carbonate(Na_2CO_3) and hydrochloric acid(HCl) solutions.The obtained samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),N_2 adsorption/desorption,temperature programmed desorption of NH_3(NH_3-TPD),solid state~(27)A1 nuclear magnetic resonance(~(27)A1 NMR),and the catalytic performances of the treated samples were tested in the xylene isomerization reaction.The results showed that the external surface area and mesoporous volume of the sample sequentially treated with 0.05 mol·L~(-1) Na_2CO_3 and 0.1 mol·L~(-1) HCl solutions reached73.9 m~2·g~(-1) and 0.162 cm~3·g~(-1),respectively.The catalytic performances of EU-1 zeolites were significantly improved,that the activity of the probe reaction increased from 23.03%to 23.61%and the selectivity increased from85.09%to 87.14%compared with those of parent sample.Furthermore,it was found that only amorphous silica and alumina species was dissolved during the post-treatment process,but the framework structure and the acidic properties of EU-1 zeolite remained intact.