有机—无机纳米复合微球在催化和相变储能方面的应用研究

发布时间：2018-01-14 22:12

本文关键词：有机—无机纳米复合微球在催化和相变储能方面的应用研究　出处：《北京科技大学》2017年博士论文　论文类型：学位论文

【摘要】：由于具有良好独特的综合性能,有机-无机纳米复合微球近几年受到了广泛的关注,在催化、能量存储和转换、传感器、光电器件及纳米生物技术等方面都有着很重要的科学和工业应用价值。有机-无机纳米复合微球中纳米尺度的复合组分不仅可以实现材料间功能性的集成,而且有可能产生出复合前纳米材料本身所不具备的特殊性质。本论文从有机-无机纳米复合微球的控制合成入手,制备了一系列具有特殊形貌、新颖结构的有机-无机纳米复合微球,探索了其在催化和储能领域的应用,并研究了材料结构与性能之间的构效关系,为有机-无机纳米复合微球的结构设计、性能调控及其在相关领域的实际应用提供了理论和实验依据。本论文的研究包括三类新型有机-无机纳米复合微球的设计制备及其在催化与储能方面应用,主要结论为:(1)以磁性纳米粒子(Cu-CuFe2O4)作为核,在有机配体均苯三甲酸(H3BTC)溶液的刻蚀下,Cu-CuFe2O4的Cu(O)组分的释放金属铜离子,原位转化为八面体微孔晶体HKUST-1,即在Cu-CuFe2O4外层形成了 HKUST-1的包覆层,制备得到core-shell结构的Cu-CuFe2O4@HKUST-1纳米复合微球,克服了传统的层层自组装法存在的反应条件苛刻、周期长且后处理复杂等缺点。将其用于催化剂时,实现了金属有机骨架化合物MOFs(Metal Organic Framework)优异的结构特性(超大的比表面积,均匀的孔径分布,可控的拓扑结构及可调的孔径)和微纳米粒子Cu-CuFe2O4催化特性的优势集成,该催化剂在低温以及以分子氧为绿色氧源的条件下,可以高效催化苄基类有机分子的氧化反应;此外,Cu-CuFe2O4磁性核心还赋予了催化剂的快速分离回收的功能;另一方面,具有微孔结构的HKUST-1壳层可保护Cu-CuFe2O4,避免催化活性组分在反应中的流失。(2)以单分散的聚乙烯吡啶微球(P4VP)为载体,通过N原子的孤对电子与Fe(Ⅲ)进行配位,实现对均相铁催化材料的固载,得到负载型铁系催化材料。通过调控单分散的聚乙烯吡啶微球的交联度,利用不同交联度的聚乙烯吡啶微球功能固载三价铁离子能力的不同,探讨了聚乙烯吡啶微球不同交联度对负载型催化材料中Fe(Ⅲ)含量的影响,获得一系列不同P4VPDVB2.5-40%-Fe(Ⅲ)催化剂;以4,4'-二氟二苯甲烷的氧化反应为探针反应,探索了不同催化剂的交联度和含铁量对催化性能的影响规律,实验结果显示,当交联剂二乙烯基苯(DVB)的含量为10%时,催化剂P4VPDVB10%-Fe(Ⅲ)展现了优良的催化性能;该催化剂具有很好的稳定性,对于苄基类底物的氧化反应具有普适性;此外,合成的催化剂的吡啶部分是能够作为一种有机碱,从而显著减少了在系统中的有机碱吡啶的用量。(3)以磺化的聚苯乙烯微球(PS)为核,通过水热法将在外层包覆介孔二氧化硅壳层,利用高温煅烧,获得介孔SiO2空心微球,并以其为载体,通过物理吸附法将相变材料十八酸(SA)固载于载体中,最终制备得到SA/介孔SiO2空心微球复合相变材料。介孔SiO2空心微球由介孔壳和空心空腔组成,具有较强毛细管力的介孔壳可以吸收十八酸到空心空腔,绝大部分的相变材料存在于空腔中,有利于十八酸的分子链自由结晶,从而导致复合相变材料的高储能效率;存在于SA与介孔SiO2空心微球的界面处的氢键及孔道的毛细作用力,对熔融的SA起到有效的定形作用;介孔SiO2空心微球提升了 SA的热导率,提升幅度在56%;且复合相变材料50次循环后仍然保持良好的相变性能。
[Abstract]:With a good overall performance unique, organic-inorganic nano composite microspheres have attracted much attention in recent years, catalysis, energy storage and conversion, sensor, photoelectric devices and nano biotechnology and other aspects have a very important application of scientific and industrial value. Composite nano scale organic-inorganic nanocomposite microspheres the points can not only realize the integration between the functional materials, and can produce specific properties of the composite materials are not available before. This paper from the controlled synthesis of organic inorganic nanocomposite microspheres with the preparation of a series of special morphology, organic inorganic nanocomposite microspheres with novel structure, explore the application in the field of catalysis and storage, and to study the structure-activity relationship between the structure and properties of materials, structural design of organic-inorganic nanocomposite microspheres, and its performance in the phase control Provides a theoretical and experimental basis for practical application in related fields. The research of this paper includes three kinds of novel organic-inorganic nano composite microsphere preparation and design in catalysis and energy storage applications, the main conclusions are as follows: (1) the magnetic nanoparticles (Cu-CuFe2O4) as the core, in the organic ligands were three Formic acid (H3BTC the etching solution), Cu-CuFe2O4 Cu (O) release of metal ion component of copper, in situ into eight surface microporous crystal HKUST-1, which formed the outer coating layer in Cu-CuFe2O4 HKUST-1, prepared by Cu-CuFe2O4@ HKUST-1 nano composite microspheres of core-shell structure, overcome the reaction conditions of traditional self-assembly method the harsh, disadvantage of long period and postprocessing is complex. For the catalyst, the metal organic framework compound MOFs (Metal Organic Framework) structure excellent characteristics (ultra large surface area, uniform The pore size distribution, pore topology controllable and adjustable) integration and catalytic properties of micro nanoparticles the advantages of Cu-CuFe2O4, the catalyst at low temperature and with molecular oxygen as the oxygen source green conditions could catalyze the oxidation reaction of benzyl base organic molecules; in addition, the rapid separation and recovery of Cu-CuFe2O4 magnetic core with the catalyst function; on the other hand, the microporous structure of HKUST-1 shell can protect Cu-CuFe2O4, avoid the catalytic active components in the reaction loss. (2) with polyvinyl pyridine microsphere (P4VP) as the carrier, through the N atom lone pair electrons with Fe (III) for coordination, to achieve homogeneous iron the supported catalytic material, supported iron catalysts. The regulation of polyvinyl pyridine microspheres monodisperse crosslinked, with different degree of crosslinking of polyvinyl pyridine microspheres supported functional ability of ferric ion is not At the same time, discussed the different degree of crosslinking of polyvinyl pyridine microspheres supported catalytic materials in Fe (III) on the content of a series of different P4VPDVB2.5-40%-Fe catalysts; (III) by oxidation of 4,4'- two fluorine two benzene methane as probe reaction to investigate the effects of different catalysts and the cross-linking degree of catalytic iron the performance, the experimental results show that when the crosslinking agent two divinyl benzene (DVB) content is 10%, the catalyst of P4VPDVB10%-Fe (III) showed excellent catalytic performance; the catalyst has good stability and universality for the oxidation of benzyl base substrate; in addition, the catalyst is part of pyridine synthesis can be used as an organic base, which greatly reduces the organic alkali pyridine in the system used. (3) with sulfonated polystyrene microspheres (PS) as the core, through the hydrothermal method in the outer cladding of mesoporous silica shell, the use of high Calcining temperature, obtained mesoporous SiO2 hollow microspheres, and takes it as the carrier, the phase change material eighteen acid through physical adsorption (SA) immobilized on the carrier, then prepared mesoporous SA/ SiO2 hollow microspheres composite phase change materials. Mesoporous SiO2 hollow microspheres by mesoporous shell and hollow cavity composed of dielectric shell has a strong capillary force can absorb eighteen acid into a hollow cavity, most of the phase change material in the cavity, is conducive to the crystallization of eighteen acid free molecular chain, which leads to high efficiency of energy storage phase change composite material; capillary force and hydrogen bond at the interface in SA and pore mesoporous SiO2 hollow micro spheres the effect of melt into amorphous SA; mesoporous SiO2 hollow microspheres enhance the thermal conductivity of SA, increase in 56%; and the composite phase change material after 50 cycles of phase change still maintain good performance.

【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TB383.1

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