共查询到19条相似文献,搜索用时 78 毫秒
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以热固性酚醛树脂为碳源,以硝酸铁为催化剂前驱体制备洋葱状碳纳米颗粒。采用酸化方法使洋葱状纳米颗粒变成不稳定的球冠状态,在高温下使球冠进行重新组装,转化为形状不规则的碳纳米管,实现了材料转化。并详细分析了洋葱状碳纳米颗粒形成与转化为碳纳米管的机理。 相似文献
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新形态的固体碳-碳纳米管的制备和应用 总被引:1,自引:0,他引:1
碳纳米管具有许多优异的性能,关于碳纳米管的制备及其应用的研究已成为炭素界以及凝聚态物理研究的前沿和热点,本文综述了各种制备方法及其应用领域。 相似文献
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Fe-Mo/MgO催化剂CVD法制备碳纳米管 总被引:5,自引:0,他引:5
研究了Fe-Mo/MgO催化剂裂解乙炔制备碳纳米管的反应条件。结果表明,反应气氛对碳纳米管的生长具有明显的影响,在Hz或Ar气氛下,所得碳纳米管的质量较差,而在N2-H2(1:1体积比)和Ar-H2(5.5:1体积比)气氛下乙炔裂解可制得纯度好、收率较高的碳纳米管。电镜观察发现在Ar-H2气氛下所制备碳纳米管的直径(平均直径为18nm)明显小于在N2-H2气氛下所制备碳纳米管(平均直径为30nm),这便于通过反应气氛的调节来控制碳纳米管的直径。用Fe-Mo/MgO做催化剂、乙炔为碳源,Ar-H2反应气氛下.850℃左右、反应30min所得碳纳米管的质量、产率最佳。 相似文献
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The application of plasma-enhanced chemical vapour deposition (PECVD) in the production and modification of carbon nanotubes
(CNTs) will be reviewed. The challenges of PECVD methods to grow CNTs include low temperature synthesis, ion bombardment effects
and directional growth of CNT within the plasma sheath. New strategies have been developed for low temperature synthesis of
single-walled CNTs based the understanding of plasma chemistry and modelling. The modification of CNT surface properties and
synthesis of CNT hybrid materials are possible with the utilization of plasma. 相似文献
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综述了近几年碳纳米管用作催化剂载体的研究进展情况,指出以碳纳米管作载体,在加氢、电催化、甲醇羰基化、合成氨、甲醇制氢等领域都取得了比常规催化剂更好的效果. 相似文献
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采用酸氧化法对作为催化剂载体的碳纳米管样品进行处理,研究不同种类的酸(硫酸、盐酸、硝酸)、不同浓度、不同温度条件对碳纳米管的影响,并利用用BET法、透射电子显微镜(TEM)进行表征。结果表明,选择在140℃的加热温度下用65%的浓硝酸溶液进行纯化效果最佳,纯后碳纳米管的比表面积明显增加,解决了碳纳米管缠绕现象,并使部分末端端口被打开。 相似文献
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O. Pitkänen N. Halonen A.-R. Leino J. Mäklin Á. Dombovári J. H. Lin G. Tóth K. Kordás 《Topics in Catalysis》2013,56(9-10):522-526
Low temperature growth process of carbon nanotubes (CNTs) over bi-metallic (Co–Fe) and tri-metallic (Ni–Co–Fe) catalysts on Si/Al/Al2O3 substrates is carried out from acetylene precursor using hydrogen, ammonia or nitrogen as a carrier in a low pressure chemical vapor deposition system. Using the tri-metallic Ni–Co–Fe catalyst template, vertically aligned CNTs of ~700 nm length could be grown already at 450 °C within 10 min using ammonia as a carrier. Within the same period of time, on bi-metallic Co–Fe catalyst templates, ~250 nm long aligned nanotubes emerged already at 400 °C in nitrogen carrier. At low temperatures most of the catalyst materials were elevated from the support by the grown nanotubes indicating tip growth mechanism. The structure of catalyst layers and nanotube films was studied using scanning and transmission electron microscopy and atomic force microscopy. 相似文献
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本文以三聚氰胺(C3N6H6)为原料,通过高温热分解法成功的制备了氮掺杂碳纳米管(N—CNTs)。据SEM和TEM图像显示,所制备的N—CNTs呈竹节状,并且直径和壁厚统一。利用FTIR图谱分析了N—CNTs的结构和官能团组成。同时,对N—CNTs的发光特性进行了研究,发现样品在蓝紫光范围内具有发光特性,这使得其在光学纳米器件方面具有潜在的应用价值。 相似文献
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Unpromoted and Mn‐Promoted Cobalt Catalyst Supported on Carbon Nanotubes for Fischer‐Tropsch Synthesis 下载免费PDF全文
Langmuir‐Hinselwood (LH) and power rate equations were applied to describe the kinetics of the Fischer‐Tropsch reaction on cobalt catalysts and manganese‐doped cobalt catalysts supported on carbon nanotubes (CNTs). LH‐based kinetics characterize the activity behavior of the unpromoted Co/CNT system satisfactorily, but fail with respect to the manganese‐promoted Co/CNT catalyst. An alternative LH equation is able to fit the experimental data, but the fitting parameters are out of the range of usual values and underrate the activity at ambient pressure regardless of manganese promotion. Application of power law rate expressions results in satisfying characterization of the kinetics in the whole CO pressure range in the promoted case and within a defined range of CO pressure in the unpromoted case. 相似文献