In situ Generation of Reticulate Micropores through Covalent Network/Polymer Nanocomposite Membranes for Reverse‐Selective Separation of Carbon Dioxide

We demonstrate the synthesis of a microporous covalent‐network membrane derived from co‐continuous blends of a porogenic urea network and a polyimide (PI). We show that the urea networks in the PI matrix may be thermally rearranged while selectively expelling small molecular fragments, thereby forming a new network bearing reticular microporous molecular pathways. The porous structures enable reverse‐selective gas separation, efficiently blocking carbon dioxide to which most polymeric membranes exhibit selective permeability. The proposed method for fabricating microporous organic membranes with highly tunable porosities using a variety of chemical structures and processing parameters is facile and shows promise for the creation of new membrane‐based molecular‐separation techniques.     

Discovery and development of microporous metal carboxylates

We have found a form of copper(II) terephthalate that occluded an enormous amount of gases such as N2, Ar, O2, and Xe. Copper(II) terephthalate is the first metal complex found capable of adsorbing gases. This complex has opened a new field of adsorbent chemistry and is recognized as a leader in the construction of microporous metal complexes. In extending the route for the synthesis of microporous complexes, we obtained many new porous materials that are widely recognized as useful materials for applications in areas such as gas storage, molecular sieves, catalysis, inclusion complexes, and surface science.     

沸石分子筛合成由微孔向中孔的飞跃

介绍了沸石分子筛合成由微孔向中孔的发展及中孔分子筛的合成近况, 比较了两类材料在合成、机理及模板作用的特殊性等方面的差异。     

Organic‐Free Synthesis of Silicoaluminophosphate Molecular Sieves

Silicoaluminophosphate (SAPO) molecular sieves are an important class of microporous materials and are useful for industrial catalysis and separations. They have been synthesized exclusively by the use of expensive and environmentally unfriendly organic structure‐directing agents. Now the synthesis of SAPO molecular sieves is reported with MER, EDI, GIS, and ANA topologies under wholly inorganic conditions. Multinuclear MAS NMR analyses demonstrate the presence of Si, Al, and P atoms in their frameworks. These SAPO materials all have unusually high framework charge densities (0.25–0.46), owing to the small size of alkali metal cations used as an inorganic structure‐directing agent. A continuous Si increase in the synthesis gel for MER‐type SAPO molecular sieves led to the formation of framework Si(0Al) units, decreasing the number of extra‐framework cations per unit cell and thus making the resulting solid useful for CO₂ adsorption.     

Features of Functionalization of MCM-41 Silica Mesoporous Molecular Sieves during Their Template Synthesis

We have shown that functionalization of MCM-41 mesoporous molecular sieves during their template synthesis using the effect of solubilization of organic hydrophobic co-condensing compounds makes it possible to obtain highly ordered mesoporous molecular sieves, with concentrations of vinyl or allyl groups covalently bonded to the surface of the silica matrix of about 3.5 mmol/g, which after sulfonation have acidic properties and exhibit catalytic activity in the process of ethyl tert-butyl ether synthesis.     

Synthesis and Applications of SAPO-34 Molecular Sieves

Silicoaluminophosphate zeolite (SAPO-34) has been attracting increasing attention due to its excellent form selection and controllability in the chemical industry, as well as being one of the best industrial catalysts for methanol-to-olefin (MTO) reaction conversion. However, as a microporous molecular sieve, SAPO-34 easily generates carbon deposition and rapidly becomes inactivated. Therefore, it is necessary to reduce the crystal size of the zeolite or to introduce secondary macropores into the zeolite crystal to form a hierarchical structure in order to improve the catalytic effect. In this review, the synthesis methods of conventional SAPO-34 molecular sieves, hierarchical SAPO-34 molecular sieves and nanosized SAPO-34 molecular sieves are introduced, and the properties of the synthesized SAPO-34 molecular sieves are described, including the phase, morphology, pore structure, acid source, and catalytic performance, in particular with respect to the synthesis of hierarchical SAPO-34 molecular sieves. We hope that the review can provide guidance to the preparation of the SAPO-34 catalysts, and stimulate the future development of high-performance hierarchical SAPO-34 catalysts to meet the growing demands of the material and chemical industries.     

SYNTHESIS AND BIOTECHNOLOGICAL APPLICATIONS OF VINYL POLYMERINORGANIC HYBRID AND MESOPOROUS MATERIALS

We describe the sol-gel synthesis of a new family of organic-inorganic hybrid materials, in which various vinylpolymers are covalently bonded to and uniformly distributed in inorganic oxide matrices. The materials can be tailored tohave both good toughness and hardness while maintaining excellent optical transparency. Doping the sol-gel metal oxideswith optically active compounds such as D-glucose results in new optical rotatory composite materials. Removal of thedopant compounds from the composites affords mesoporous oxide materials, which represents a new, nonsurfactant-templated route to mesoporous molecular sieves. We have successfully immobilized a series of enzymes and other bioactiveagents in mesoporous materials. Catalytical activities of the enzyme encapsulated in mesoporous materials were found to bemuch higher than those encapsulated in microporous materials.     

Themed Issue Dedicated to Professor Ruren Xu onthe Occasion of his 90th Birthday

Aluminophosphate(AlPO) and silicoaluminophosphate(SAPO) molecular sieves are an important class of open-framework crystalline materials with wide applications thanks to their molecular-scale selectivity, moderate/strong acidity and excellent (hydro)thermal stability. In recent decades, the manufacturing of new microporous solids with ordered structures has been widely investigated and many effective methods have been developed, which enriches the material types and broadens their applications beyond the traditional use as catalysts and adsorbents. However, the development on the synthesis of AlPO/SAPO molecular sieves is still insufficient and lags behind the needs of applications. Herein, we summarize the work on the seed-assisted synthesis of AlPO/SAPO molecular sieves compared with the zeolite synthetic system, aiming to prompt the synthesis and application of AlPO/SAPO molecular sieves.     

Synthesis of a Specified,Silica Molecular Sieve by Using Computationally Predicted Organic Structure‐Directing Agents

Crystalline molecular sieves are used in numerous applications, where the properties exploited for each technology are the direct consequence of structural features. New materials are typically discovered by trial and error, and in many cases, organic structure‐directing agents (OSDAs) are used to direct their formation. Here, we report the first successful synthesis of a specified molecular sieve through the use of an OSDA that was predicted from a recently developed computational method that constructs chemically synthesizable OSDAs. Pentamethylimidazolium is computationally predicted to have the largest stabilization energy in the STW framework, and is experimentally shown to strongly direct the synthesis of pure‐silica STW. Other OSDAs with lower stabilization energies did not form STW. The general method demonstrated here to create STW may lead to new, simpler OSDAs for existing frameworks and provide a way to predict OSDAs for desired, theoretical frameworks.     

新型复合分子筛的合成和催化应用

 系统地归纳总结了最近几年引起人们广泛关注的复合分子筛的研究进展,包括微孔-微孔复合分子筛、微孔-介孔复合分子筛、微孔-大孔复合分子筛及微孔-介孔-大孔复合分子筛的合成和应用近况. 并对复合分子筛的发展前景进行了展望.     

A Family of Molecular Sieves Containing Framework‐Bound Organic Structure‐Directing Agents

Organic structure‐directing agents (OSDAs), such as quaternary ammonium cations and amines, used in the synthesis of zeolites and related crystalline microporous oxides usually end up entrapped inside the void spaces of the crystallized inorganic host lattice. But none of them is known to form direct chemical bonds to the framework of these industrially important catalysts and adsorbents. We demonstrate that ECR‐40, currently regarded as a typical silicoaluminophosphate molecular sieve, constitutes instead a new family of inorganic‐organic hybrid networks in which the OSDAs are covalently bonded to the inorganic framework. ECR‐40 crystallization begins with the formation of an Al–OSDA complex in the liquid phase in which the Al is octahedrally coordinated. This unit is incorporated in the crystallizing ECR‐40. Subsequent removal of framework‐bound OSDAs generates Al‐O‐Al linkages in a fully tetrahedrally coordinated framework.     

金属磷铝(MeAPO)分子筛的合成及催化活性

本文用水热法合成了MAPO-5、CoAPO-5、CoMAPO及MAPO-36四种分子筛。对新合成的样品进行了XRD、IR、SEM及原子吸收光谱分析。确认各样品皆为分子筛结构,初步证实金属Mg和(或)金属Co进入到分子筛的结构骨架。金屑磷铝分子筛比磷铝分子筛裂化活性提高很大,从分析产物C_3及C_4看出各样品的低催化活性对应于低的C_4/C_3·C_4/C_3值反映了分子筛的窄小空腔或弯曲通道。     

海泡石原位晶化合成NaY分子筛的研究

首次用海泡石为硅源、高岭土为铝源,在水热条件下原位晶化合成NaY分子筛,采用粉末X射线衍射仪、电子扫描电镜等测试手段对所合成样品进行表征分析,着重考察晶化温度和投料配比对产品相对结晶度的影响.研究结果表明,NaY分子筛的形成受晶化温度的影响最大,随温度的升高,产品的相对结晶度显著提高,晶化温度升至100℃时,得到结晶度较高的NaY分子筛晶体.在原位晶化体系中,随n(SiO2)/n(Al2O3)减小,其相对结晶度增大;增加体系的n(Na2O)/n(SiO2)和减小n(H2O)/n(Na2O)都增大产品的相对结晶度;n(SiO2)/n(Al2O3)在投料比影响因素中占主导地位.     

多孔材料负载金催化剂的制备与应用*

本文综述了微孔材料和介孔材料负载型金催化剂的制备、表征与应用研究的最新进展,从多孔载体的选择（氧化物、微孔分子筛、介孔氧化物、介孔分子筛和介孔碳材料）、金的最新负载方法（沉积-沉淀法、溶胶-凝胶法、原位法/一步法和化学气相沉积法）与表征及其催化性能（一氧化碳低温氧化、氢气/氧气直接合成过氧化氢、直接合成环氧丙烷和有机物的选择性氧化）等方面详尽地评述了微孔材料和介孔材料负载型金催化剂研究概况。同时,提出了多孔材料负载金催化剂存在的一些问题,并展望了其研究和发展的方向。     

Synthesis of micro- and mesoporous molecular sieves at room temperature and neutral pH catalyzed by functional analogues of silicatein

By using functional mimics of the protein silicatein alpha together with organic structure directing agents, it was possible to produce different mesoporous and microporous molecular sieves at room temperature and neutral pH.     

氩吸附法研究多级孔分子筛的孔结构

采用不同方法分别制备了双介孔分子筛、介微孔分子筛及介孔沸石材料,利用氩吸附法并结合XRD技术表征了多级孔分子筛的孔结构。探讨了适用于多级孔分子筛的孔径分布计算方法,揭示了不同类型吸附等温线与孔径分布、孔型及孔容等之间的关系。研究表明,对于多级孔分子筛、微孔和介孔的孔径分布分别用SF法和BJH法计算较适宜,全孔分析可用NLDFT法计算。通过对TS-1介孔沸石的孔结构分析发现, TPAOH 在改性制备介孔TS-1的过程中起到了生成介孔及促进二次晶化的双重作用。     

Supramolecular Interactions and Morphology Control in Microwave Synthesis of Nanoporous Materials

Application of a microwave technique to the conventional hydrothermal process is gaining importance, especially, in the synthesis of nanoporous materials. This microwave technique is regarded as a novel synthesis tool because it gives several beneficial advantages such as homogeneous nucleation, rapid synthesis, formation of uniform crystals, and small crystallites, facile morphology control, energy efficiency and so on. Recently, it was found that it offers an efficient way to control the crystal morphology, size and orientation, and even crystalline phase which are required for many emerging applications of nanoporous materials. This review summarizes recent work on the microwave effect, supramolecular interactions and control of crystal morphology upon microwave synthesis of nanoporous materials performed by the present authors. Synthesis and morphology control of nanoporous materials such as ZSM-5, zeolite beta, metallosilicates, AlPO, MCM-41, SBA-15, SBA-16, etc. have been accomplished with microwave irradiation. In particular, the rapid nucleation and crystallization of ZSM-5 zeolite under microwave irradiation made it possible to enable the continuous microwave synthesis, implying a great industrial and technological importance. The formation of nanoporous materials, especially, silicate or aluminosilicate molecular sieves was described on the basis of supramolecular interactions between organic template molecules and silicate species under microwave irradiation. Besides decreasing synthesis time, it was duly demonstrated that the microwave technique provides an effective way to control particle size distribution and macroscopic morphology in the synthesis. Moreover, for the application of these porous materials, microwave-induced nanofabrication of microporous and mesoporous materials is more important than that of simple porous materials.     

Combinatorial Methods for the Synthesis of Aluminophosphate Molecular Sieves

Automatic dispensing of reagents into autoclave blocks followed by synthesis, isolation, and automated structure analysis with X-ray diffractometry represents an efficient methodology for the combinatorial synthesis of microporous materials. The figure shows a typical diffractogram of as-synthesized AFI-type molecular sieves taken with a CCD camera.     

Polymers of intrinsic microporosity (PIMs): bridging the void between microporous and polymeric materials

Novel types of microporous material are required for chemoselective adsorptions, separations and heterogeneous catalysis. This concept article describes recent research directed towards the synthesis of polymeric materials that possess microporosity that is intrinsic to their molecular structures. These polymers (PIMs) can exhibit analogous behaviour to that of conventional microporous materials, but, in addition, may be processed into convenient forms for use as membranes. The excellent performance of these membranes for gas separation and pervaporation illustrates the unique character of PIMs and suggests immediate technological applications.     

具有MFI结构的La-Si ZSM-5分子筛的合成

首次合成了稀土元素掺杂的具有MFI结构的La-Si ZSM-5分子筛,并采用各种技术对所合成的分子筛进行了表征.XRD衍射表明所合成的微孔材料具有典型的MFI结构,N2吸脱附、FT-IR及SEM测试结果均表明镧原子进入了分子筛骨架.