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1.
李积慧  陈建新 《化工进展》2020,39(6):2235-2240
金属有机框架是由金属中心与有机配体自组装形成的一类结构可设计的新型多孔材料。吸附分离是金属有机框架的重要用途之一。本文介绍了以金属有机框架为多孔平台设计合成具有目标导向的官能化金属有机框架的途径以及官能化金属有机框架在二氧化碳与氮气、甲烷分离,烷烃与烯烃分离,低碳烷烃等小分子气体分离纯化中的作用。表明官能化的金属有机框架由于官能团活性位点的存在,在二氧化碳、烯烃、烷烃等气体小分子分离中相对未经修饰的金属有机框架具有更高的分离选择性。官能化的金属有机框架的目标导向使其在化工分离领域具有更广阔的应用前景。目前材料合成难以量产限制了官能化的金属有机框架在化工分离方面的普及,随着合成方法的不断简化官能化金属有机框架在化工分离中会有更广泛的应用。  相似文献   

2.
多孔碳纳米球由于可实现尺寸、形貌、孔结构以及表面基团等的可控合成制备,其负载/镶嵌的金属粒子又兼具高活性和高热稳定性等,在多相催化领域中受到越来越多的关注。本文追溯了多孔碳纳米球形貌调控的发展历程及其负载金属催化剂在催化反应领域中的应用。归纳了不同形貌的多孔碳纳米球及其制备方法和原理,详细对比了各个方法的优缺点;阐述了多孔碳纳米球负载金属催化剂的性能和碳球结构与形貌之间的构效关系;总结了目前碳球作为催化剂载体亟需解决的问题是碳球的多孔结构及其负载尺寸可控和空间匀称分布的金属粒子的可控合成,并展望了其发展方向是进一步研究和探索结构可调、经济可行的碳纳米球制备方法,真正实现工业化应用。  相似文献   

3.
双介孔炭材料具有两种不同的介孔孔径,可以满足不同直径分子的传输需要,并且具有惰性的材料表面,有利于改性,因此日益受到研究者的广泛关注.本文较为详尽地介绍了目前双介孔炭材料的制备方法及应用现状,指出有效控制孔结构、孔径分布及进一步开发双介孔炭材料的应用是未来研究的主要方向.  相似文献   

4.
卢贝丽  刘杏  尹铸  黄彪 《化工进展》2021,40(2):778-788
苯胺是重要的化工原料和合成中间体,通过硝基苯的催化还原反应可以方便地制备苯胺类化合物。多孔碳材料因其高比表面积、发达的孔隙结构和容易回收等特点在催化领域越来越受到重视,然而其应用受到自身活性位点缺乏和化学惰性的限制。杂原子掺杂可以增强碳材料的表面极性,调节电子结构,改善其催化性能,可作为硝基苯催化还原反应的有效催化剂。本文对近年来掺杂多孔碳材料在硝基苯催化还原反应中的研究进展进行了总结。本文概述了氮掺杂型多孔碳材料、共掺杂型多孔碳材料、负载贵金属的掺杂多孔碳材料和负载廉价金属的掺杂多孔碳材料这4种主要的掺杂多孔碳材料的制备方法,并详细介绍了不同掺杂多孔碳材料在催化硝基苯催化还原反应时的催化性能、可能的催化活性位点以及催化机理。最后,指出目前掺杂多孔碳材料催化硝基苯还原还需要解决反应选择性、催化剂催化活性和生产成本等问题,以生物质为前体,开发共掺杂型和二元双金属负载的掺杂多孔碳材料是未来的重要发展方向之一。  相似文献   

5.
胡航标  张涛  崔征  唐盛伟 《化工进展》2016,35(11):3576-3584
以氧化石墨烯-羧基碳纳米管水溶液为原料,葡萄糖酸β内酯为交联促进剂,通过冷冻干燥法制得负载有多乙烯多胺的氧化石墨烯-羧基碳纳米管三维多孔气凝胶。通过在制备过程中改变多乙烯多胺的加入量可以调节其负载量。FTIR、XRD、TG、SEM、XPS、Raman、N2吸脱附等测试表征发现:多乙烯多胺通过酰胺键与基体连接,所得材料呈蜂窝状,且比表面积、孔容和平均孔径随胺类负载量的增加而逐渐降低,引入多乙烯多胺后的气凝胶材料通过化学作用实现CO2吸附。在200kPa、328K下,多乙烯多胺含量为55.8%的改性吸附剂的CO2吸附量可达3.9mmol/g,为相同条件下未改性吸附剂的9.8倍。结果表明,将多乙烯多胺、氧化石墨烯和羧基碳纳米管制备成三维蜂窝状多孔材料能有效提高CO2吸附性能。  相似文献   

6.
以多种氰基离子液体为前驱体,采用高温碳化法直接制备多孔碳氮材料,系统考察了离子液体前驱体阳离子结构、阴离子种类及合成条件等因素对碳化材料比表面积、氮元素含量及氮种类的影响,并研究其对CO2的吸附性能。结果表明,阴离子在聚合过程中起模板剂的作用。合成材料主要呈介孔结构,比表面积最高达732.6 m2/g,氮含量最高为9.9wt%,在温度25℃、压力1.8 MPa条件下,CO2的吸附量最高达20.9wt%。多孔碳氮材料经180℃真空加热后可完全脱附再生,再生稳定性良好。  相似文献   

7.
张家赫  原野  王明  王志  王纪孝 《化工学报》2021,72(2):709-726
金属有机框架(MOFs)因其大孔隙率、高比表面积和规则可调的孔径结构等优势受到了广泛关注,然而该材料较差的热塑性和力学性能限制了其可加工性,不利于大规模工业应用。为解决此问题,研究者们将聚合物作为多孔材料的一部分,通过直接或间接的方法合成了一种三维且高度多孔的材料——聚合物-金属有机框架(polymer-metal-organic frameworks, polyMOFs)。此材料兼具MOFs出色的性能与聚合物的可加工性,在气体分离、生物医用和催化等领域具有广阔的应用前景。本文综述了polyMOFs的三种合成方法,包括合成后聚合、单晶到单晶转换和直接合成法,介绍了三种方法的特点与不足,并展望了未来polyMOFs的发展方向。  相似文献   

8.
炭微球具有化学稳定性好、电导率优良、比表面积大、孔结构丰富等优点,在吸附、催化等领域具有广阔的应用前景,引起了研究人员的广泛关注。酚醛基炭微球以酚醛树脂为前体,经高温炭化制备而成,这种制备方法工艺简单、对设备要求低、产率高,而且通过调整反应物和反应条件可实现对炭微球结构和功能性的精细调控,从而更好地满足实际应用的需求。概述了酚醛基炭微球的最新研究进展,分为小粒径炭微球制备、多孔炭微球制备和功能化炭微球制备三个方面,并介绍了酚醛基炭微球在储能、吸附和电催化领域的应用,最后对其未来发展方向进行了展望。  相似文献   

9.
炭微球具有化学稳定性好、电导率优良、比表面积大、孔结构丰富等优点,在吸附、催化等领域具有广阔的应用前景,引起了研究人员的广泛关注。酚醛基炭微球以酚醛树脂为前体,经高温炭化制备而成,这种制备方法工艺简单、对设备要求低、产率高,而且通过调整反应物和反应条件可实现对炭微球结构和功能性的精细调控,从而更好地满足实际应用的需求。概述了酚醛基炭微球的最新研究进展,分为小粒径炭微球制备、多孔炭微球制备和功能化炭微球制备三个方面,并介绍了酚醛基炭微球在储能、吸附和电催化领域的应用,最后对其未来发展方向进行了展望。  相似文献   

10.
The objective of this work is the synthesis of highly functionalized hybrid organic/inorganic materials by the polycondensation of bis[3-(trimethoxysilyl) propyl]amine in the presence of surfactants. High contents of amine groups were achieved by carrying out the syntheses without an inorganic cross-linker. The silsesquioxanes obtained had a mesoporous structure. The stability of their porous system in the absence of an inorganic cross-linker was enhanced by the precursor’s bridged structure. The material structures were studied by FT-IR spectroscopy, Porosimetry, X-Ray Diffraction and Small Angle X-Ray Scattering methods. A material prepared in the presence of dodecylamine as a template had a higher surface area and narrower pore size distribution while the use of sodium dodecyl sulfate resulted in the formation of mesopores with a wide size distribution. Surface amine groups in silsesquioxanes were accessible for adsorption of small molecules of acidic nature.  相似文献   

11.
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。  相似文献   

12.
Hierarchically porous zeolites are promising candidates in catalytic conversion of relatively bulky molecules, and their syntheses have attracted significant attention. From both industrial and scientific perspectives, different carbon materials have been widely employed as hard templates for the preparation of hierarchically porous zeolites during the past two decades. In this review, the progress in synthetic strategies using carbon materials as templates is comprehensively summarized. Depending on the affinity between the carbon templates and zeolite precursors, the substantial strategies for synthesizing hierarchical zeolites are introduced in direct templates and indirect templates. Direct templates methods, by which the carbon materials are directly mixed with precursors gel as hard templates, are first reviewed. Then, we discuss the indirect templates method (crystallization of carbon-silica composites), by which the carbon is produced by in situ pyrolysis of organic-inorganic precursors. In addition, the technique of encapsulating metal species into zeolites crystals with the assistance of carbon templates is also discussed. In the conclusion part, the factors affecting the synthesis of carbon-templated hierarchically porous zeolites are remarked. This review is expected to attract interest in the synthesis strategies of hierarchically porous zeolites, especially cost-effective and large-scale production methodologies, which are essential to the industrial application of hierarchical zeolites.  相似文献   

13.
功能化聚四氟乙烯微孔膜的研究进展   总被引:3,自引:0,他引:3  
功能化PTFE微孔膜兼具PTFE微孔膜的优异特性及功能高分子的特殊性能,选择性透过、催化、传输药物、抗菌、质子交换等特殊功能的聚四氟乙烯(PTFE)微孔膜极具应用潜力。本文综述了PTFE微孔膜的特性,总结了近年来采用辐射接枝、表面沉积、涂覆或共混等方法功能化PTFE微孔膜的最新研究进展及其在化工、医学、服装、电子等领域功能化应用的最新成果,并指出目前存在的问题,对今后的研究提出了展望。  相似文献   

14.
以石墨片微元构建的多孔碳材料作为活性炭的结构模型,采用巨正则蒙特卡罗方法(GCMC)和分子动力学方法(MD),从分子层面研究甲烷和甲苯在活性炭中的吸附和扩散特性. 结果表明,石墨片微元大小对多孔碳材料吸附甲烷和甲苯有一定影响,37个碳环构成的多孔碳材料是最佳的吸附结构;甲烷气体在活性炭材料中扩散较快,甲苯在活性炭中扩散较慢,随碳环碳原子数增加,气体在多孔碳材料中的自扩散系数逐渐增大;引入基团会使最优密度向高密度方向偏移,用不同基团表面改性的吸附量顺序为羟基>氨基>羧基>未改性,基团引入会改善材料的孔结构,有利于吸附量的增加.  相似文献   

15.
超级电容器因其高功率密度、超高速充放电、高稳定性等突出特点在电化学储能装置中引起人们极大关注。在当前开发的电极材料中,碳材料因其良好的导电性、孔隙率及形貌可调等特点备受青睐。传统的单一微孔碳材料具有较大的比表面积,但存在利用率低、孔道堵塞、电阻较大等问题。针对上述问题,研究人员对分级结构多孔碳材料开展了广泛的研究。本工作通过分析调研国内外相关文献,详细评述了现有分级多孔碳材料制备方法,简要介绍了各方法的原理和优缺点,同时对分级多孔碳应用于超级电容器时的性能改进方法进行了总结,并展望了其未来发展方向,为将来分级多孔碳的进一步研究提供参考。  相似文献   

16.
Poly(methyl methacrylate) (PMMA) multi-walled carbon nanotubes (MWCNTs) nanocomposites were synthesized by several methods using both pristine and surface functionalized carbon nanotubes (CNTs). Fourier transform infrared (FTIR) spectroscopy was used to characterize the presence and types of functional groups in functionalized MWCNTs, while the dispersion of MWCNTs in PMMA was characterized using scanning electron microscopy (SEM). The prepared nanocomposites were foamed using carbon dioxide (CO2) as the foaming agent. The cell morphology was observed by SEM, and the cell size and cell density were calculated via image analysis. It was found that both the synthesis methods and CNTs surface functionalization affect the MWCNTs dispersion in the polymer matrix, which in turn profoundly influences the cell nucleation mechanism and cell morphology. The MWCNTs are efficient heterogeneous nucleation agents leading to increased cell density at low particle concentrations. A mixed mode of nucleation mechanism was observed in nanocomposite foams in which polymer rich and particle rich region co-exist due to insufficient particle dispersion. This leads to a bimodal cell size distribution. Uniform dispersion of MWCNTs can be achieved via synergistic combination of improving synthesis methodology and CNTs surface functionalization. Foams from these nanocomposites exhibit single modal cell size distribution and remarkably increased cell density and reduced cell size. An increase in cell density of ∼70 times and reduction of cell size of ∼80% was observed in nanocomposite foam with 1% MWCNTs.  相似文献   

17.
Supercapacitors are promising for high power application in the recent years. In particular, the conversion of simple and available carbon materials into economic and high performance electrical devices receives excellent scientific and technological interest. This paper reports a one-step strategy for synthesizing hierarchical porous carbon derived from phenolic resin (PR), which is then used to configure electric double-layer capacitors (EDLCs). Here, a carbon material with a flexible porous structure, large specific surface area, and high graphitization degree is prepared using potassium ferrate (K2FeO4) to catalytically activate PR and to realize synchronous carbonization and graphitization. This method overcomes the disadvantage of time-consuming, high-cost, and environmentally unfriendly. In addition, the as-prepared carbon material has a high specific surface area (1086 m2 g?1) and a large pore size (3.07 nm), which can increase the transfer rate of electrolyte ions. The specific capacitance of the obtained electrode material is 315 F g?1 at 1.0 A g?1, and the optimized electrode material has an ultra-long cycle lifetime (capacitance retention rate is 96.3% after 10,000 cycles). Thus, the hierarchically Fe-doped porous carbon material derived from PR material is expected to realize high rate capacitance for supercapacitor applications.  相似文献   

18.
活性炭纤维的改性研究和在烟气脱硫中的应用   总被引:1,自引:0,他引:1  
活性炭纤维是在碳纤维工业基础上发展起来的新一代吸附材料,相比于活性炭(粒状和粉状),活性炭纤维具有比表面积大、微孔丰富、孔径小且分布窄、吸附量大等优点。介绍了活性炭纤维的表面结构特点和化学组成,综述了活性炭纤维在国内外的改性现状及在烟气脱硫中的应用,并展望了活性炭纤维的发展方向。  相似文献   

19.
A simple heterogeneous synthesis of pure modified porous polysiloxane SiO2 by condensing a functionalized C,C‐pyridylpyrazole with a 3‐glycidoxy‐propyltrimethoxy‐silane silylant agent, previously anchored on a silica surface is reported. The epoxide group was opened yielding a receptor pendant group bonded to the inorganic surface. The surface modification (MS) was characterized by elemental analysis, infrared spectra, nitrogen adsorption–desorption isotherm, BET surface area and B.J.H. Pore sizes. The new material exhibits good chemical and thermal stability determined by thermogravimetry curves. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

20.
Synthesis of structured silicon carbide materials can be accomplished using wooden materials as the carbon source, with various silicon impregnation techniques. We have explored the low cost synthesis of SiC by impregnation of carbon from wood with SiO gas at high temperatures, which largely retains the structure of the starting wood (shape memory synthesis). Suitably structured, porous SiC could prove to be an important type of catalyst support material. Shape memory synthesis (SMS) has earlier been tried on high surface area carbon materials. Here we have made an extensive study of SMS on carbon structures obtained from different types of wood.  相似文献   

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