锰氧八面体分子筛的制备及应用研究进展

锰氧八面体分子筛具有多孔结构、温和的表面酸碱性、混合价态的锰离子和优异的离子交换性,被广泛应用于多相催化、电池材料和吸附材料等领域。本文介绍了锰氧八面体分子筛的化学组成,对其孔结构、氧化还原性能及酸碱性等理化性质予以总结,简述了水热法、回流法、微波法、溶胶-凝胶法和固相法等常用制备方法。锰氧八面体分子筛可应用于CO催化氧化、有机物催化氧化、CO₂活化利用和费托合成等催化领域,尤其对CO和挥发性有机物有较高的氧化活性,在电池材料和吸附材料等非催化领域也有重要的应用前景。最后指出了当前锰氧八面体分子筛研究中存在的问题,未来工作应探索更高效的合成方法,深入认识其催化作用机理,进一步拓宽该材料的应用范围。     

氧化锰八面体分子筛催化性能研究进展

氧化锰八面体分子筛(OMS-2)具有多孔结构、混合价态的锰离子、温和的表面酸碱性和优良的离子交换性,对污染物尤其是挥发性有机污染物(VOCs)具有独特的去除效果,在适当的催化条件下,转化率可达100%。氧化锰八面体分子筛的合成方法有多种,不同合成方法对其催化效率具有很大影响,其中,掺杂金属离子在某些情况下可显著提高对污染物质的转化率以及目标产物选择性,尤其是掺杂贵金属Ag和Pd后,效果更为优异。从氧化锰八面体分子筛的合成方法、催化应用和作用机理等方面综述氧化锰八面体分子筛的研究进展。     

Recent Advances in Solid State NMR of Small Molecules in Confinement

In the past years, porous media have become a major focus of materials science, due to their versatile properties, such as high surface area, low specific weight, high surface functionality, and the ability to customize their surface properties. Applications of porous media range from catalysis to separation media to gas storage. All of the mentioned applications involve the introduction of guest molecules into the pores. For efficient application of the materials, it is essential to know the behavior of these introduced molecules in the confined state. Solid state (ss) NMR gives a unique insight into the dynamics, the guest-host interactions, and the binding sites of porous materials and is probably the most powerful characterization method for probing a huge variety of real-life systems. Recent results in research of microporous zeolites and periodically mesoporous silica (PMS) materials using NMR will be highlighted.     

咔咯锰、铁和钴配合物的合成与应用研究进展

金属咔咯是具有独特的光化学、光物理、光生物性质的多功能卟啉类配合物。特别是一些含有过渡金属如锰、铁、钴为中心离子的金属咔咯配合物,在新型催化剂、抗肿瘤药物、电化学传感器以及纳米材料等领域都具有较好的应用前景。对含有锰、铁、钴中心金属离子的单核和双核咔咯配合物的合成方法及在相关领域的应用进展进行了综述,为该类配合物的进一步研究和应用提供有益参考。     

N掺杂多孔碳材料研究进展

通过掺杂氮原子对多孔碳材料进行功能化,可强化多孔碳材料固有的优异性能并赋予其新功能,从而拓宽其在各领域的应用范围。近年来,研究者相继开发了一系列技术方法,已制备得到多种结构特异、性能优异的氮掺杂多孔碳材料。本文基于氮掺杂多孔碳材料的最新研究进展,详细介绍了利用液相模板法、化学气相沉积法、氨气后处理法、化学活化法和水热法等制备氮掺杂多孔碳材料的方法,评述了各种方法的特点及局限性,并简要介绍了该类材料在电池催化、气体吸附分离、储氢及污染气体脱除等方面的应用,指出了氮掺杂多孔碳材料工业应用的规模化制备发展方向。     

Utilization of Electrolytic Manganese Residues in Production of Porous Ceramics

Electrolytic manganese residues (EMR) are one of industrial by‐products generated during the production of electrolytic manganese metal. To reduce the EMR hazard to environment and invent value‐added materials, porous ceramics were prepared by the pore‐forming method with EMR and various additives. The influences of the incorporation of different additives, sintering temperature, and molding pressure on properties of porous ceramics were investigated. Properties such as apparent porosity, water absorption, bulk density, and compression strength have been measured. The EMR‐based porous ceramics were also characterized by XRD, SEM, BET‐specific surface area, and BJH pore size distribution measurement. It revealed that the appropriate mode was the sample containing 20 wt% carbon powder, 7.5 wt% dolomite, and 5 wt% kaoline, under which the ceramics with the properties of high apparent porosity (69.70%), high compressive strength (6.97 MPa), and good acidity–alkali stability were obtained successfully. The comprehensive performance of EMR‐based porous ceramics makes them advantageous to use as nonhazardous and valuable materials showing promising potential applications, which not only is a promising new approach to improve the resource utilization of EMR but also can promote the manganese industry's sustainable and healthy development and protect and improve ecological environment.     

Reactive ballistic deposition of nanostructured model materials for electrochemical energy conversion and storage

Porous, high surface area materials have critical roles in applications including catalysis, photochemistry, and energy storage. In these fields, researchers have demonstrated that the nanometer-scale structure modifies mechanical, optical, and electrical properties of the material, greatly influencing its behavior and performance. Such complex chemical systems can involve several distinct processes occurring in series or parallel. Understanding the influence of size and structure on the properties of these materials requires techniques for producing clean, simple model systems. In the fields of photoelectrochemistry and lithium storage, for example, researchers need to evaluate the effects of changing the electrode structure of a single material or producing electrodes of many different candidate materials while maintaining a distinctly favorable morphology. In this Account, we introduce our studies of the formation and characterization of high surface area, porous thin films synthesized by a process called reactive ballistic deposition (RBD). RBD is a simple method that provides control of the morphology, porosity, and surface area of thin films by manipulating the angle at which a metal-vapor flux impinges on the substrate during deposition. This approach is largely independent of the identity of the deposited material and relies upon limited surface diffusion during synthesis, which enables the formation of kinetically trapped structures. Here, we review our results for the deposition of films from a number of semiconductive materials that are important for applications such as photoelectrochemical water oxidation and lithium ion storage. The use of RBD has enabled us to systematically control individual aspects of both the structure and composition of thin film electrodes in order to probe the effects of each on the performance of the material. We have evaluated the performance of several materials for potential use in these applications and have identified processes that limit their performance. Use of model systems, such as these, for fundamental studies or materials screening processes likely will prove useful in developing new high-performance electrodes.     

A hot isostatic process for fabricating porous materials

Hot isostatic processing (HIP) is the latest method to produce open porous materials, such as ceramics or metals. In this review paper, features and applications of HIPed porous materials are described. Sintering behavior under high pressure gas is also discussed in order to understand how porous materials are obtained by this method. HIPed porous materials have higher open porosity, higher mechanical strength, narrower pore size distribution and higher fluid permeability than conventionally sintered ones. These excellent properties of HIPed porous materials are due to the enhanced surface diffusion caused by the high gas pressure. By applying these excellent properties of HIPed porous materials, filters, grinding wheels, and porous electrodes for electrochemical analysis can be produced with better properties than products made by conventional sintering.     

Fabrication and characterization of magnetic porous silicon with curie temperature above room temperature

In this study, we demonstrate a completely novel synthesis route for producing magnetic porous silicon. The magnetic properties of this material are induced by manganese atoms. The Mn-doping in Si is achieved by ion implantation. A subsequent anodization of the substrate is done to turn it into porous silicon. Several characterization techniques, such as transmission electronic microscopy, atomic force microscopy and photoluminescence are combined to probe the structural and the optical properties of this material. Furthermore, temperature and magnetic field dependent magnetization is analyzed using superconducting quantum interference device. In addition to the well-reported structural and optical properties of the porous silicon, our Mn-doped porous silicon samples exhibit a magnetic behavior with a curie temperature (T_C) higher than room temperature. These results indicate that the magnetic porous silicon can be integrated with microelectronics and photonics technologies to produce new devices, such as magnetophotonic crystals and polarized emitting diodes.     

层次孔碳材料：结构设计、功能改性及新能源器件应用

发展电化学能源存储与转换技术是我国的长期重大需求。作为电化学能源器件中的关键材料,多孔碳材料已成为当前能源材料与化工领域的研究热点。层次孔碳材料是一类新型的多孔碳材料,同时兼具不同尺寸与功能的微孔、中孔或大孔。研究者通过对层次孔碳材料可控设计,已制得一系列孔结构、孔骨架及表面化学性质和微/纳拓扑形貌各异的新型层次孔碳及其复合材料,极大地提升了其能源存储和转化性能。本综述总结了近年来有关层次孔碳材料的结构设计、可控制备及其在电化学能源器件应用领域等方面的研究进展,并对其未来发展提出了建议与展望。     

Advanced NMR Cryoporometry

Accurate structural characterization of mesoporous solids is of importance for potential applications and for better understanding of properties of natural porous materials. Among different characterization techniques, thermoporometry has several beneficial features, such as applicability to wetted and soft materials. In this review, we discuss recent advancements concerning nuclear magnetic resonance cryoporometry allowing for a notable improvement of the accuracy of this method.     

Supercritical Fluid Technologies for Ceramic-Processing Applications

The applications of supercritical fluid technologies for ceamic processing are reviewed. The novel physical and chemical properties of these densified gases are summarized and related to their use as solvents and processes benefit from the unique properties of supercritical fluids. The rapid expansion of supercritical fluid solutions provides a technique for producing fine uniform powders and thin films of widely varying materials. Supercritical drying technologies allow the formation of highly porous aerogel products with potentially wide application. Hydrothermal processes leading to the formation of large single crystals and microcrystalline powders can also be extended into the supercritical regime of water. Additional applications and potential applications are identified in the areas of extraction of binders and other additives from ceramic compacts, densification of porous ceramics, the formation of powders in supercritical microemulsions, and in preceramic polymer processing.     

绿色多功能材料--多孔陶瓷

多孔陶瓷是一种新型材料,由于其具有较低的热传导等优良性能,而被广泛地应用于众多科学领域.笔者综述了多孔陶瓷的制备工艺、性能及应用,尤其是讨论了多孔陶瓷在各个领域的应用,最后展望了多孔陶瓷的发展前景及今后的发展方向.     

多孔陶瓷及其在清洁方面的应用

多孔陶瓷是一种新型材料,由于其具有化学稳定性等优良特性,而被广泛地应用于众多科学领域。综述了多孔陶瓷的特点、分类、制备工艺,并着重论述其在清洁方面的应用。展望多孔陶瓷的发展前景。     

PolyHIPEs: Recent advances in emulsion-templated porous polymers

Porous polymers with well-defined porosities and high specific surface areas in the form of monoliths, films, and beads are being used in a wide range of applications (reaction supports, separation membranes, tissue engineering scaffolds, controlled release matrices, responsive and smart materials) and are being used as templates for porous ceramics and porous carbons. The surge in the research and development of porous polymer systems is a rather recent phenomenon. PolyHIPEs are porous emulsion-templated polymers synthesized within high internal phase emulsions (HIPEs). HIPEs are highly viscous, paste-like emulsions in which the major, “internal” phase, usually defined as constituting more than 74% of the volume, is dispersed within the continuous, minor, “external” phase. This review focuses upon the recent advances in polyHIPEs involving innovations in polymer chemistry, macromolecular structure, multiphase architecture, surface functionalization, and nanoparticle stabilization. The effects of these innovations upon the natures of the resulting polyHIPE-based materials (including bicontinuous polymers, nanocomposites, hybrids, porous ceramics, and porous carbons) and upon the applications involving polyHIPEs are discussed. The advances in polyHIPEs described in this review are now being used to generate new families of porous materials with novel porous architectures and unique properties.     

多孔陶瓷材料测试技术研究

多孔陶瓷材料因为其特殊的多孔结构而表现出多种特性,如:特殊的渗透率、热传导率、强度、捕获效率和电导率等,从而使其作为一种多功能材料而获得广泛应用。本文综合论述了多孔陶瓷材料微观结构表征及各种性能的测试技术,以及相关的仪器设备,展望了多孔陶瓷测试技术的发展前景。     

Structuring adsorbents and catalysts by processing of porous powders

Microporous materials such as zeolites, metal organic frameworks, activated carbons and aluminum phosphates are suitable for catalysis and separation applications. These high surface area materials are invariably produced in particulate forms and need to be transformed into hierarchically porous structures for high performance adsorbents or catalysts. Structuring of porous powders enables an optimized structure with high mass transfer, low pressure drop, good heat management, and high mechanical and chemical stability. The requirements and important properties of hierarchically porous structures are reviewed with a focus on applications in gas separation and catalysis. Versatile powder processing routes to process porous powders into hierarchically porous structures like extrusion, coatings of scaffolds and honeycombs, colloidal processing and direct casting, and sacrificial approaches are presented and discussed. The use and limitations of the use of inorganic binders for increasing the mechanical strength is reviewed, and the most important binder systems, e.g. clays and silica, are described in detail. Recent advances to produce binder-free and complex shaped hierarchically porous monoliths are described and their performance is compared with traditional binder-containing structured adsorbents. Needs related to better thermal management and improved kinetics and volume efficiency are discussed and an outlook on future research is also given.     

绿色多功能材料--多孔陶瓷

多孔陶瓷是一种新型材料,由于其具有较低的热传导等优良性能,而被广泛地应用于众多科学领域。本文综述了多孔陶瓷的制备工艺、性能及应用,特别是详尽的讨论了多孔陶瓷在各个领域的应用,最后展望了多孔陶瓷的发展前景及今后的发展方向。     

Graphene and Carbon Nanotube Polymer Composites for Laser Protection

This paper reviews recent advances in the nanotube and graphene polymer composites synthesized in our laboratories for laser protection application, i.e., OL. We first discuss the mechanisms involved in the polymer nanocomposites for OL and the Z-scan technique used to measure the nonlinear optical properties of the materials in question. Subsequently, the design, synthesis, characterization, and OL properties of the representative nanotube and graphene polymer composites are introduced, followed by a prospect for use of carbon nanomaterial polymer composites for optical limiting.     

Progress of superhydrophobic porous materials

Porous materials such as metal organic framework materials (MOFs), covalent organic framework materials (COFs), organic porous polymers (POPs), etc., have been used widely used in the fields of separation, catalysis, gas storage and drug release due to their diversity, designability, controllability and functionalization of pores. Despite these promising applications, some of the porous materials suffer from moisture-sensitivity and instability in aqueous media due to their inherent structural features. To overcome this problem, endowing them with hydrophobicity is an effective strategy. However, designing superhydrophobic porous materials has certain challenges. In this work, the progress of MOFs, COFs and POPs with (super-)hydrophobic property is introduced. Issues related to their design strategy, structures, and practical applications such as catalysis, oil/water separation and gas storage and separation were analyzed. Additionally, the current problems and the future research directions of the hydrophobic porous materials were discussed.