钾长石合成13X分子筛的实验研究

以钾长石为主要原料,经焙烧和水热合成工艺,合成了１３Ｘ分子筛粉．采用正交设计法确定了各工艺过程中的最佳工艺参数．合成分子筛的ＸＲＤ图、晶胞参数、ＳＥＭ图、ＤＴＡ图、化学成分、硅铝比与理想的１３Ｘ分子筛相似;吸附量达到国家化学工业产品标准．     

模板剂合成锰八面体分子筛及其催化燃烧二甲醚的性能研究

以离子液体[bmin]NO3调控的溶胶凝胶法合成了氧化锰八面体分子筛(OMS-2),并采用TG-DSC、XRD、低温N2吸附、TEM、FT-IR、UV-vis、O2-TPD以及H2-TPR等方法对固体材料的结构进行了表征,考察了制备材料的二甲醚催化燃烧反应的催化性能.结果表明,合成的OMS-2材料属于cryptomelane一维隧道结构,由于离子液体同时作为模板导向剂和还原剂,因而使得OMS-2的外形以一维纳米线为主.O2-TPD和H2-TPR实验表明,OMS-2材料具有丰富的氧物种,低温下易还原,因而在二甲醚催化燃烧中表现出了良好的催化性能.二甲醚催化燃烧的起燃温度T10%为180℃,而完全燃烧温度T90%为190℃,反应产物仅有CO2和H2O.     

聚合物中分子筛的合成

聚合物可作为空间限制剂或介孔导向剂在一定程度上控制分子筛的尺寸和形貌,进而影响分子筛的反应活性、寿命和产物选择性。综述了近年来国内外聚合物中合成分子筛的新进展。系统介绍了聚合物中空心/核壳结构分子筛、介孔分子筛以及复合分子筛的合成;简要介绍了聚合物的添加对分子筛尺寸和形貌的影响。     

利用含有模板剂的SAPO-34分子筛制备高效铜基催化剂

氮氧化物污染已经成为一个严重的环境问题。利用分子筛催化剂进行选择性催化还原(SCR)处理氮氧化物是最有效的方法之一。为了降低现有催化剂的制备成本, 本工作直接利用含有模板剂的分子筛浆料为原料, 通过预处理、离子交换及一次焙烧的方法制备Cu-SAPO-34催化剂。采用XRD、BET、TG、ICP、XPS、SEM、TPR、TPD及NH₃-SCR等对制备的Cu-SAPO-34样品进行表征, 并对离子交换过程中的pH条件进行了优化。研究结果表明: 利用含模板剂的分子筛浆料制备得到催化剂含有2.43% Cu、立方晶型完整、酸性较强以及催化还原性能优秀。在200~450℃下, NO转化率超过80%, 并且在300℃时转化率达到最高97.8%。与使用商品化SAPO-34制备的催化剂相比, 两者具有相似的微观结构和SCR性能。SAPO-34分子筛中少量模板剂的存在对最终制备得到的Cu-SAPO-34催化剂的性能影响很小。因此采用含有模板剂的分子筛浆料制备高效Cu-SAPO-34催化剂是可行的。     

协同模板机理合成六方介孔分子筛[Ti]-MCM-41

[Ti]-MCM-41介孔分子筛是在空气中采用协同模板机理水热合成出来的,其中Ti离子是处在MCM-41的骨架孔壁中.合成所用硅源为工业级水玻璃,液晶模板剂为十六烷基三甲基溴化铵.对3种基本因素进行了考察,一是搀杂的Ti源不同,分别是四氯化钛和钛酸四丁酯;二是合成时溶液pH值不同;三是合成时Ti/Si摩尔比不同.样品表征分别采用XRD粉末X光衍射、N2吸附-脱附等温线(77K)对样品的结构性能进行了表征.     

模板法合成中孔炭材料

在综合分析无机模板法和有机模板法的基础上,提出矿物模板法和复合模板法是制备中孔炭的有效方法.矿物模板法原料价格低廉、来源广泛.复合模板法综合了软模板和硬模板的优点,能够拓展中孔炭的结构、性能和应用领域.以矿物模板制备的炭材料具有良好的电学、医学性能等,有望获得良好性价比的中孔炭材料.     

无模板法可控合成多层次结构二氧化钛微球

以1,4-二氧六环为溶剂,采用溶剂热法成功实现无模板法可控合成二氧化钛多层次结构微球。通过系统改变反应体系中浓盐酸与四异丙醇钛(TTIP)相对物质的量比能够有效调控二氧化钛形貌。当浓盐酸与TTIP物质的量比控制在0(或0.7或0.9)、1.8、3.6与5.7时,所得产物分别为纳米颗粒构建二氧化钛微球、纳米棒修饰二氧化钛微球、纳米棒花菜结构以及纳米棒海胆结构。在成功进行形貌调控的基础上,进一步探讨了二氧化钛多种结构的形成机理,并对其光催化产氢性能进行了表征。研究发现,在这4种结构中,纳米棒修饰二氧化钛微球具有最佳的光催化性能,这可能是由于同时存在金红石和锐钛矿两种晶型而形成异质结结构所导致。     

双模板剂B-EU-1/ZSM-5复合分子筛的快速合成及催化应用

以不同氢氧化物做碱源合成B-EU-1/ZSM-5复合分子筛, 并比较各平衡阳离子的结构导向作用及其形貌特征, 发现钠离子的导向作用最强, 且合成复合分子筛的表面较光滑、无明显晶面界限。对合成样品进行了TG-DTG、N₂吸附-脱附和NH₃-TPD分析。结果表明: 双模板剂一步法合成的复合分子筛模板剂脱除的失重率为5.67%, 小于机械复合分子筛的失重率7.31%, 复合分子筛的比表面积、孔容和微孔平均孔径均有所增大, 同时其酸强度、酸量都增大, 有利于二甲苯优先从复合分子筛的孔道结构中扩散出来。将分子筛应用于甲醇转化制二甲苯催化反应, 结果显示, 双模板剂一步法合成的复合分子筛催化产物油相中芳烃的选择性最高达到66.72%, 芳烃中二甲苯的含量为46.15%, 二甲苯中对二甲苯的含量达到30.75%。这是由于B-EU-1/ZSM-5催化剂的特殊孔道结构具备择形效应, 使得分子动力学直径较小的二甲苯分子优先从其孔道中扩散出来。     

模板剂对MCM-41介孔分子筛结构的影响

以微硅粉为硅源,利用水热合成法成功制备出MCM-41介孔分子筛,利用XRD、N2吸附曲线和TEM等测试方法对样品进行了表征,结果表明,模板剂的用量对样品的结构具有显著的影响,当CTAB／SiO2的摩尔比为0．15时,样品的结构有序性最高;混合模板剂可明显提高样品的比表面积和孔容,合成的MCM-41介孔分子筛比表面积从299m2／g提高到837．3m2／g,孔容从0．051cm。／g提高到0．79cm3／g。     

ZSM-5分子筛膜的一次水热法合成及工艺探索

以四丙基氢氧化铵(TPAOH)为模板剂在自制的硅酸盐陶瓷支撑体上利用原位水热法一次合成了ZSM-5分子筛膜.讨论了影响合成分子筛膜的因素(碱度、晶化时间以及模板剂的用量),确定了最佳合成配比和晶化时间.利用X射线粉末衍射(XRD)和扫描电镜(SEM)对合成的粉末及膜进行了晶相分析和膜表面形貌表征,用N2对经过多次焙烧后的分子筛膜进行了渗透性能恻试.     

铜型抗菌沸石的合成(英文)

用液相、固相离子交换法将沸石与具有抗菌性能的铜离子合成抗菌沸石。用正交法确定了两种方法的较佳条件 ,并进行了比较。液相、固相离子交换法合成铜型抗菌沸石的较佳条件为硫酸铜浓度为 0 .1mol·L- 1 ,硫酸铜用量为 0 .0 2mol;温度分别为 60℃和 5 5 0℃ ,反应时间分别为 4h和 1h。尝试利用微波加热法合成抗菌沸石。微波加热合成抗菌沸石可以减少反应时间和节约能源     

有机氟阴极电泳涂料的制备工艺

水性含氟涂料既具有氟树脂的耐候、耐污、耐腐蚀等性能,又具有水性涂料环保、安全等性能,目前国内对此研究还不够深入。以环氧树脂为主体,选择合适的丙烯酸单体、有机氟单体对其改性,合成了同时具备环氧树脂、丙烯酸树脂、氟树脂性质的阳离子型含氟环氧丙烯酸树脂,并以此为主体树脂制备出水稀释型阴极电泳涂料,重点探讨了含氟单体的种类和数量、反应温度、反应时间等因素对树脂合成以及漆膜性能的影响。结果表明:在合适的工艺条件下,可以得到高耐腐蚀性、耐老化性、自洁性的电泳漆膜。     

Preparation of high silica microporous zeolite SSZ-13 using solid waste silica fume as silica source

Silica fume (SF) is a kind of solid waste that produced in the process of industrial silicon smelting. The disposal of SF for environmental problem is of great urgency. Here, a facile and novel one-step approach of high silica microporous materials SSZ-13 (SF-SSZ-13) were hydrothermally synthesized using silica fume (SF) as silica source. This method requires significantly shorter reaction times (48?h) compared to conventional SSZ-13. The as-synthesized SF-SSZ-13 exhibited high purity structure, popcorn-like morphology, and a large BET surface area of 545.74?m²?g^?1. Additionally, on the basis of controlled growth under different hydrothermal times, the formation mechanism of the SF-SSZ-13 outlined for further extension to other materials. The results on time- and energy-efficient of SF-based preparation of SSZ-13 pave the way for the reducing the cost of production of raw materials and decreasing environment load of solid waste, and also extend the application of silica fume.     

Heterogeneous Catalysis in Zeolites,Mesoporous Silica,and Metal–Organic Frameworks

Crystalline porous materials are important in the development of catalytic systems with high scientific and industrial impact. Zeolites, ordered mesoporous silica, and metal–organic frameworks (MOFs) are three types of porous materials that can be used as heterogeneous catalysts. This review focuses on a comparison of the catalytic activities of zeolites, mesoporous silica, and MOFs. In the first part of the review, the distinctive properties of these porous materials relevant to catalysis are discussed, and the corresponding catalytic reactions are highlighted. In the second part, the catalytic behaviors of zeolites, mesoporous silica, and MOFs in four types of general organic reactions (acid, base, oxidation, and hydrogenation) are compared. The advantages and disadvantages of each porous material for catalytic reactions are summarized. Conclusions and prospects for future development of these porous materials in this field are provided in the last section. This review aims to highlight recent research advancements in zeolites, ordered mesoporous silica, and MOFs for heterogeneous catalysis, and inspire further studies in this rapidly developing field.     

燃烧合成中的有机物

对燃烧合成中的有机物及其作用机制进行了总结和论述。介绍了有机物的低温氧化特征——冷火焰及其应用前景。     

Hydrogen Isotope Separation in Confined Nanospaces: Carbons,Zeolites, Metal–Organic Frameworks,and Covalent Organic Frameworks

One of the greatest challenges of modern separation technology is separating isotope mixtures in high purity. The separation of hydrogen isotopes can create immense economic value by producing valuable deuterium (D) and tritium (T), which are irreplaceable for various industrial and scientific applications. However, current separation methods suffer from low separation efficiency owing to the similar chemical properties of isotopes; thus, high‐purity isotopes are not easily achieved. Recently, nanoporous materials have been proposed as promising candidates and are supported by a newly proposed separation mechanism, i.e., quantum effects. Herein, the fundamentals of the quantum sieving effect of hydrogen isotopes in nanoporous materials are discussed, which are mainly kinetic quantum sieving and chemical‐affinity quantum sieving, including the recent advances in the analytical techniques. As examples of nanoporous materials, carbons, zeolites, metal–organic frameworks, and covalent organic frameworks are addressed from computational and experimental standpoints. Understanding the quantum sieving effect in nanospaces and the tailoring of porous materials based on it will open up new opportunities to develop a highly efficient and advanced isotope separation systems.     

纳米立方LiF的液相制备及表征

以NH₄F和LiOH·H₂O为原料、无水乙醇为溶剂和结晶控制剂,采用液相法合成前驱体低温烧结制备纳米级LiF粉末。利用X射线粉末衍射、扫描电镜、透射电镜和激光粒度仪等分析手段对样品进行表征。结果表明,前驱体的主要成分为LiF、NH₄F和LiOH·H₂O;热分析结果表明,NH₄F的分解温度约为190℃。在220~400℃烧结后得到的样品具有单一的LiF立方晶体结构,颗粒饱满,大小均匀,形貌良好,粒径的平均尺寸为80 nm。     

Nanoparticle Synthesis in Engineered Organic Nanoscale Reactors

In this review, the recent achievements in the synthesis of inorganic nanomaterials inside the spatially confined volume of individual micro‐ and submicroreactors (emulsions, micelles, organized thin films, polyelectrolyte capsules, etc.) are presented. The advantages and shortcomings of each type of microreactor are discussed. Particular attention is paid to polyelectrolyte capsules as confined microreactors with controlled shell permeability and the possibility of shell engineering on the nanolevel, thus tailoring different functionalities. Nanomaterials synthesized inside a confined multifunctional microreactor have several advantages: i) absence of particle aggregates, ii) amorphous or metastable crystal phases, and iii) unique composite inorganic/inorganic and inorganic/organic structures.     

Increasing the Efficiency of Organic Solar Cells by Antireflection Coatings Based on Fluoride Composites

Results are presented obtained in measurements of current–voltage characteristics of organic solar cells with and without antiref lection coatings produced by melting in a solar furnace of 95 : 5 and 55 : 45 wt % MgF₂ and CaF₂ fluoride mixtures. The relative increase in the efficiency of the organic solar cells was 3.2% in the first case and 3.3% in the second.