【作者】 郭春雨；

【导师】 王成扬；

【作者基本信息】 天津大学 ， 化学工艺， 2007， 博士

【摘要】 多孔炭是炭材料的一个重要的分支,传统的多孔炭已经实现产业化并应用到化工、环境保护、食品等行业;新型多孔炭如高比表面积活性炭、中孔炭等具有极大的发展潜质和提升空间,在催化剂载体、双电层电容器、储氢等高科技含量技术领域发挥着重要的作用。针对多孔炭的形成机理、优化制备条件、扩大应用范围进行研究与探讨,具有十分重要的理论意义和实用价值。本论文以沥青系前驱体的结构特征作为切入点,考察前驱体之间内部微结构存在的差异对多孔炭材料最终性能的影响。实验发现,各向同性前驱体微晶结构缺陷较多,非晶碳或边缘碳含量高,反应活性较强,容易与活化剂发生更为充分的化学反应而制造更多的孔隙,在碱/炭比为4:1时形成“双峰型”孔径分布,比表面积高达2913m2/g。以中间相炭微球为前驱体进行系统的活化实验工作,探寻前驱体结构特性、热处理条件、多孔炭微结构及吸附性能之间存在的客观规律,组装的双电层电容器比电容高达271F/g。实验从前驱体内部结构缺陷和活化反应两方面进行活化机理的探讨,可以将各向异性碳质前驱体在相对缓和的条件下(碱/炭比为2:1)制备成高比表面积(2412m2/g)、高中孔率(41.5%)多孔炭材料;以活性中间相炭微球作为原料、膨胀石墨作为模板进行多孔炭/膨胀石墨复合材料的制备,从膨胀石墨特有的结构为出发,研究如何利用固体空间网络结构的搭建为电子的传导提供良好的通道,从而在不改变多孔炭孔结构的前提下提高电极材料的双电层电容性能,复合材料的双电层比电容较纯多孔炭电极提高20-30F/g。本论文以前驱体结构为出发点,在前驱体内部人为地制造结构缺陷,为活化反应充分地进行创造有利条件;将传统的化学活化与催化活化制备方法相结合,采用新型的化学-催化活化方法制备高比表面积、高中孔率的多孔炭材料;将中间相炭微球以化学活化方法制备活性炭微球,应用于双电层电容器电容特性的研究,拓宽了中间相炭微球的应用研究领域。更多还原

【Abstract】 Activated carbon is an important branch of carbonaceous materials. Activated carbon products made with traditional activation methods were used in chemical engineering, environment protection and food purification. Meanwhile, new activated carbons with high surface area or high mesopore content had more potential for development, which play an important role in catalytic support, electrical double-layer capacitor and hydrogen storage. It is significant for theory and practice to study on the mechanism of etching, preparation conditions and application of activated carbons.In this paper, relationship between performance of activated carbon and structure of precursors was investigated from the structural characteristics. Isotropic precursor with more noncrystal or edge carbons can be etched by KOH easily and became high surface (2913m2/g) activated carbon with double peaks type pore size distribution. Mesocarbon microbeads were utilized to be precursors for activation and the impersonality among structure characteristics of precursors, heat treatment conditions and microstructure and adsorption abilities of activated carbons was discussed. Electrical double-layer capacitors using activated mesocarbon microbeads as electrode were taken shape and the max specific capacitance reached 271F/g. Activation mechanism was explained by structural defects and chemical etching. Activated carbon with high surface area (2412m2/g) and high mesopore content (41.5%) was gained under lower KOH/C ratio (2:1) from anisotropic precursor. Activated mesocarbon microbeads/expanded graphite composites were prepared and specific capacitance was discussed. Conductivity was increased through establishing the solid-network without changing the adsorption abilities of activated mesocarbon microbeads. The specific capacitances of pure porous carbons were increased about 20-30F/g, respectively.In this paper, chemical activation took advantage of man-made structural defects and porous carbon with higher performance was gained with novel chemical-catalytic activation method. Activated carbons made from mesocarbon microbeads were put into the investigating of electric double layer capacitor and the application of mesocarbon microbeads was widened.更多还原