首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Porous carbon monoliths have been prepared by template assisted routes using porous concrete as the template. Due to its good workability, porous concrete is a suitable template to produce carbon monoliths with defined shape. The pore widths of the obtained monoliths are distributed over a broad range from the micropore to the macropore region. Such materials are a promising base for developing construction components which can be applied in adsorption devices or catalytic systems.  相似文献   

2.
Monolithic forms are particularly suitable when using porous carbon materials in flow through apparatus. One method to synthesize these materials is the template‐assisted synthesis. Porous carbon monoliths have been prepared using porous concrete as a template. Systematic investigations of the mechanical stability have shown the potential of these materials for technical applications. It could be proven that the monoliths are stable against compressive stress and flow‐through of water, respectively.  相似文献   

3.
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   

4.
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   

5.
多孔炭材料具有导电性好、结构稳定、资源丰富、价格低廉的天然优势,既可直接作为电极材料,构建炭基电化学储能器件,又可与非炭电活性材料复合,起到传输电子、缓冲体积膨胀及调节界面反应的作用,在电化学储能器件中一直发挥着不可或缺的作用。结合本文作者课题组的研究工作,本文总结了多孔炭制备及孔结构和形貌的调控方法,分析了各方法的优缺点;并以超级电容器、锂离子/钠离子电池和锂硫电池为代表,阐述了多孔炭材料在电化学储能领域的作用及应用研究现状,讨论了电化学储能器件对多孔炭材料的结构与性能要求,指出了多孔炭在电化学储能应用中存在的局限性,并对多孔炭在这些储能领域的研究和发展趋势做出展望。  相似文献   

6.
木质素是一种具有三维网状分子结构、含有大量芳香基团和高含碳量等特点的天然高分子,其在制备多孔炭领域具有巨大潜力。多孔炭在催化剂和能源储存领域具有极大的应用前景。以来源于制浆造纸和生物炼制行业的副产物工业木质素作为原料制备多孔炭应用于能源储存、吸附、催化剂载体等领域,可实现工业木质素在碳基功能材料领域的高附加值循环再利用。本文详细综述了目前木质素多孔炭的常用制备方法和微结构特性的调控方法,总结归纳了各制备方法的主要特点以及影响木质素多孔炭微结构与性能的关键因素;重点综述了近些年对木质素多孔炭孔道结构调控方面的研究,归纳了孔调控的方法;此外,总结了木质素多孔炭在超级电容器、锂离子电池、吸附剂和催化剂载体领域中的应用研究现状,讨论了催化和储能材料对木质素多孔炭的微结构特性要求。总结并展望了木质素多孔炭在制备与应用中面临的机遇和挑战。  相似文献   

7.
郑超  康凯  周术元  宋华  白书培 《化工进展》2021,40(7):3803-3812
多孔炭材料具有较大的比表面积和发达的孔隙结构,是吸附有毒有害气体的关键材料,备受环境、化工、军事化学等领域的关注。多孔炭材料对有毒有害气体的吸附性能受气氛中水分子竞争吸附的影响,研究多孔炭材料对水分子的吸附行为是复杂环境下吸附分离有毒有害气体的基础,对改进多孔炭材料的表面官能团组成和孔结构具有重要的指导意义。基于此,本文综述了国内外关于水分子在多孔炭材料上吸附的机理、过程和影响因素,探讨了水分子作为示踪分子用于多孔炭材料结构表征的潜在可能,并对未来吸附理论的研究方向和指导新型吸附材料设计的应用前景进行展望。  相似文献   

8.
煤在新型炭材料制备中的应用   总被引:2,自引:2,他引:2  
炭材料具有很多特性,随着工业技术的发展,它的地位越来越重要,以煤为原料制备新型炭材料已经引起人们的普遍关注并具有十分乐观的发展前途.从多孔炭材料、富勒烯类炭纳米材料和锂离子电池电极三方面综述了以煤为原料制备新型炭材料的研究和应用开发的新进展,阐述了煤作为一种廉价原料的优势,提出了煤作为制备原料在三个方面的发展方向.  相似文献   

9.
模板法合成一维纳米材料的研究进展   总被引:4,自引:0,他引:4  
模板合成法是一种控制并改进纳米微粒在结构材料中的排列、改善纳米材料性能的有效手段,可以用来合成导电聚合物、碳、金属、半导体以及其他无机纳米材料,在电池、光催化、药物合成和生命科学等领域得到了广泛的应用。介绍了以多孔氧化铝、多孔氧化硅、高分子聚合物以及其他物质为模板合成碳、金属、半导体和聚合物等高度取向的纳米一维管状或线状材料的研究进展。  相似文献   

10.
葛坤玉  陈祥迎 《广州化工》2014,(18):80-81,109
针对油污废水对环境的污染问题,本文提出可用高温炭化海藻酸钠制备的多孔炭材料解决油污水问题。实验首先考察不同炭化温度得到的多孔炭材料对油污水的吸附性能影响;其次多孔炭材料的用量对油污水处理的影响;最后考察了多孔炭材料在油污水中的吸附时间对油污水处理的影响。实验结果证明,当炭化温度为900℃时,多孔炭材料的吸附能力最强,油污剩余量最少;当多孔炭材料的质量与油污水的体积比为1 g∶0.5 L时油污水的含量最低;当吸附时间为6 h时,油污水的含量最低。结果表明,多孔炭材料用于油污水的治理具有广泛的应用前景,可望在未来油污水处理方面发挥更大的作用。  相似文献   

11.
Synthesis of novel, carbon porous replicas of vesicular siliceous materials has been described. The original siliceous materials consist of small, spherical structures resembling onions, known in the literature as multilamellar vesicles (MLVs). They have been characterized with a number of analytical methods that allow one to determine its 3-D structure and basic parameters of the pore system. Carbonaceous materials, made similarly of onion-like porous structures, have been obtained using a standard procedure to form replicas. They have been characterized by the same methods as those applied to the parent materials.  相似文献   

12.
模板法为各种有机和无机纳米材料的可控和定向合成开辟了一条全新的技术途径,近年来已经成为材料制备研究领域引人注目的新方法。本文就迄今为止模板法在制备具有规则结构的多孔炭材料领域的研究动态进行综述,介绍了多孔炭材料的模板法制备、应用前景及其可能的形成机制。  相似文献   

13.
氮吸附法表征多孔材料的孔结构   总被引:15,自引:0,他引:15  
采用低温氮吸附法表征了具有不同孔结构的碳纳米管、碳分子筛、活性炭、分子筛和石墨化炭黑等多孔材料的孔径分布。氮吸附一脱附等温线利用康塔公司NOVA3000在相对压力0.001-1范围内测定。五种材料的比表面积在100-1000m2/g之间。低压下的吸附等温线和高压下的脱附等温线分别用HK方法和BJH方法解析,结果表明:五种多孔材料既含有发达的微孔,又含有一定数量的中孔。孔径大小及其分布的细微信息在色谱采样中能够预测吸附剂的吸附性能,也是新型多孔材料开发的关键。  相似文献   

14.
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...  相似文献   

15.
Graphene and other carbon materials have been combined with various silicon (Si) nanostructures to accommodate the volume change of Si and enhance their electrical conductivity. However, for most of the formed hybrids, their low initial Coulombic efficiency (CE), fragile structures and poor stability cannot meet the practical application of battery. In this work, inspired by the structure and composition of reinforced concrete, a Si nanoparticles embedded in porous carbon/graphene (Si-C/G) electrode is fabricated through directly calcining a Si-polyacrylonitrile/graphene oxide precursor on a current collector. In this concrete-like structure, amorphous carbon, the carbonization product of polyacrylonitrile, acts as the “cement” and binds all components together. The flexible graphene network effectively enhances the strength, flexibility and conductivity of the electrode, as does the reinforcing rod framework in concrete. This carbon/graphene scaffold can accommodate the volume expansion of Si and isolate Si from electrolyte. Such Si-C/G electrode with small surface area and compact structure achieves a high initial CE of 78% and a reversible capacity of 1711 mAh g−1, as well as outstanding rate and cycling performances.  相似文献   

16.
Heteroatom doping of carbon materials may become the “Next Big Thing” in materials science further enhancing research concerning carbon nanostructures. In particular, the S-doped porous carbons have gained a great deal of attention in the last few years. They are already proven to be versatile functional materials with a wide range of potential applications, including heterogeneous catalysis, sorption, as well as in the areas of energy conversion and storage. To date, a few approaches have been developed to intrinsically blend sulfur into the carbon matrix. Yet there is still a need to design new porous structures with controllable porosity and well defined chemical status of sulfur doped into the carbon matrix. In this review, we summarize recent reports on the preparation of S-doped carbons, with special emphasis on porous carbons with intrinsically doped sulfur. The effect of S-doping on the properties determining applications is delineated. Special attention is paid to differentiate between elemental sulfur impregnation, intercalation, surface functionalization and S bulk doping of porous carbons. To this end, synthesis and applications of S-impregnated, S-functionalized and S-intercalated carbons are shortly discussed before the intrinsically S-doped carbons are presented in detail. The importance of the sulfide –C–S–C– system for the properties of S-doped carbon is stressed. At the very end, Se-doped carbons are shortly presented as a promising next generation of chalcogen-doped carbon.  相似文献   

17.
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   

18.
Coal gangue (CG), which is mainly generated during coal excavation, mining, and coal washing, is an industrial solid waste that is recognized as an environmental pollutant. The ever-increasing amount of CG produced is a serious threat to the ecological environment and property safety, especially in China, which is the largest coal producer and consumer in the world. Considerable studies have investigated means for utilizing CG worldwide. This review summarizes and discusses various porous inorganic materials made from CG, including cement-based porous materials, porous bricks, porous ceramics (cordierite and mullite) and glasses, porous geopolymers, zeolites, aerogels, and porous carbon materials. Different preparation processes and performances of each type of porous inorganic materials were reviewed. Porous CG-based materials can be used as promising adsorbents for the removal of various pollutants and have good potential for use in construction industry as well as catalyst material applications. Besides, porous materials obtained from CG have also been tested as slow-release fertilizers after the absorption of phosphate, as electrode materials, and as oil-in-water separation agents. The systematic summary of porous materials based on CG aims at promoting high-value-added applications for this waste. Future research directions for the use of CG as a raw material are also presented.  相似文献   

19.
过量的磷流入水体易导致水体富营养化等环境问题。吸附法由于操作方便、经济高效等特点被广泛应用于水体磷酸盐的去除。有序多孔材料具有孔道规则,比表面积大,孔容大等特点,其作为载体可有效提高活性物种的分散性,从而提高吸附剂去除磷酸盐的效率。该文综述了基于不同有序多孔材料合成的吸附剂应用于水体磷酸盐去除的进展,主要包括有序多孔碳材料、有序多孔硅材料和金属有机框架。讨论了基于有序多孔材料吸附剂的磷酸盐吸附性能、主要吸附机制、影响因素及回收利用等。总结了基于有序多孔材料吸附剂吸附磷酸盐存在的问题,展望了其未来研究方向及应用前景。  相似文献   

20.
过量的磷流入水体易导致水体富营养化等环境问题,吸附法由于操作方便、经济高效等特点被广泛应用于水体磷酸盐的去除。有序多孔材料具有孔道规则,比表面积大,孔容大等特点,其作为载体可有效提高活性物种的分散性,从而提高吸附剂吸附磷酸盐的效率。综述了基于不同有序多孔材料的吸附剂应用于水体磷酸盐去除的进展,主要包括有序多孔碳材料、有序多孔硅材料和金属有机框架。讨论了基于有序多孔材料吸附剂的磷酸盐吸附性能、主要吸附机理、影响因素及回收利用。总结了基于有序多孔材料吸附剂吸附磷酸盐存在的问题,展望了其未来研究方向及应用前景。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号