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2005年01月18日

【期刊论文】影响炭质中间相形成和发展的因素-Ⅰ.原料和热缩聚条件的影响

王成扬, 李同起, 王成扬*, 刘秀军

,-0001,():

-1年11月30日

摘要

炭质中间相是制备炭材料,尤其是高附加值炭材料的优质前驱体。它在高性能炭纤维、超高功率电极用针状焦、锂离子二次电池负极、超高比表面积活性炭及催化剂载体、泡沫炭等领域得到了较好的应用。本文综述了原料和热缩聚条件对炭质中间相形成和发展的影响,这些影响因素包括原料的种类、热缩聚温度、反应压力和停留时间等。通过讨论指出,由于炭质中间相涉及的原料种类多样,热缩聚制备过程中涉及的反应、物相复杂,因此,在制备特定性能的产品时,应针对产品的特定性能要求来选择原料、设定热缩聚条件,以制得具有最佳结构和性能的产品。

炭质中间相, 中间相炭微球(, MCMB), , 沥青, 结构, 缺陷

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2005年01月18日

【期刊论文】Preparation of platinum supported on carbon blacks with different surface chemical characteristics

王成扬, Jia Rong-Li, Wang Cheng-Yang, Zhu Bin

Third International Conference on Fuel Cell Science, Engineering and Technology May 23-25, 2005, Ypsilanti, Michigan,-0001,():

-1年11月30日

摘要

In a study of the preparation of Pt/C eletrocatalysts, a set of modified Vulcan XC-72 carbon black supports have been prepared by nitric acid or hydrogen peroxide oxidation, or thermal treatment in nitrogen flow. The supports obtained by these methods had largely identical pore structure, but different from the amount of surface oxygen-containing groups. The physical and surface chemical nature of the supports was characterized by XPS, BET, FTIR, and acid-base titration. The above pre-treatment-carbon supported Pt/C electrocatalysts were prepared by the impregnation-reduction method with formaldehyde as the reducing agent, H2PtCl6 as precursor. The effect of the amount of surface oxygen-containing groups of Vulcan XC-72 carbon black on the Pt/C catalysts dispersion was studied by the characterization with XRD and TEM. It was discovered that decreasing the amount of surface oxygen-containing groups on carbon supports favored the dispersion of platinum on the Pt/C catalysts.

electrocatalysts,, platinum,, carbon,, surface oxygen-containing groups

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2005年01月18日

【期刊论文】Mesophase structures formed in the system of coal tar pitch with the presence of inorganic impurities

王成扬, Cheng-Yang Wang*, Tong-Qi Li, Xiu-Jun Liu, Jia-Ming Zheng, Hui Wang

,-0001,():

-1年11月30日

摘要

Carbonaceous mesophase is an excellent precursor for preparing high performance carbon materials. The structure of carbonaceous mesophase could be affected by the raw material and the condensation conditions. In the present work, the influence of inorganic impurities in coal tar pitch on the structures of the mesophase formed was investigated by adding some inorganic materials, such as nano-scale silicon dioxide and micron-scale alumina. Scanning electronic microscopy (SEM) was used to observe the morphology and cross-sectional texture of the mesophase spheres. It was found that inorganic impurities would influence the structure of the mesophase and the size of inorganic materials was a key factor for affecting the final structure of the mesophase. The microtexture of the MCMB formed in the coal tar pitch without inorganic impurities tends to be global type. Nano-scale silicon dioxide changed the forming mode of MCMB from homogeneous nucleation to heterogeneous nucleation and the MCMB formed was built up with small spheres with the size of less than 3.5μm. Micron-scale alumina particles could not change the mode of nucleation of MCMB but were enwrapped in the MCMB and distorted the microtexture layers of MCMB.

A., Coal tar pith,, mesophase, C., Scanning electronic microscopy, D., Defects,, texture.,

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2005年01月18日

【期刊论文】Differences in structure of mesophase spheres prepared through homogeneous and heterogeneous nucleation

王成扬, Cheng-Yang Wang*, Tong-Qi Li, Xiu-Jun Liu

,-0001,():

-1年11月30日

摘要

Mesophase spheres were prepared through homogeneous and heterogeneous nucleation from two coal tar pitches with some and nearly without quinoline insolubles. The pitches suffered thermal condensation in a stainless steel reactor at 440 and 410℃ for 1 or 7h, respectively. SEM was introduced as a useful tool to detect the structures of the two kinds of mesophase spheres. As a result of the paper, it was found that the structure of mesophase spheres prepared through homogeneous nucleation was Brooks-Taylor type, which is consistent with the analysis result of optical microscopy. Whereas, the structures of the heterogeneous nucleation mesophase spheres were complex, which were parallel in parts of the structure.

A., Coal tar pith,, Carbon microbeads,, Mesophase, C., Scanning electron microscopy,, Optical microscopy

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    天津大学,天津

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