A Study on the Effects of Carrier Gases on the Structure and Morphology of Carbon Nanotubes Prepared by Pyrolysis of Ferrocene and C2H2 Mixture

Carbon nanotubes （CNTs） were prepared using different carrier gases, with ferrocene as the catalyst precusor and acetylene as the carbon source. The effects of ammonia and nitrogen as carrier gases on the structure and morphology of CNTs were investigated. Transmission electron microscope （TEM）, high-resolution electron microscope （HRTEM）, scanning electron microscope （SEM） and X-ray diffraction （XRD） were employed to characterize the products and the catalyst. Experiment results show that the CNTs grown in N2 gas exhibited cylindrical and tubular structure, while a bamboo-like structure was observed for the CNTs grown in NH3 gas. Moreover, vertically aligned CNTs were obtained on an A12O3 disk when NH3 was used as the carrier gas. The carrier gas also exerted influence on the shape of the catalyst. Based on the theory of active centers of catalysis and combined with the particle shape of the catalyst, a growth model for the vertically aligned CNTs on the substrate is given.     

单原子催化材料在电化学氢循环应用中的研究进展

单原子催化剂(SACs)是一类仅含有孤立的单个金属原子作为催化活性中心的催化材料. 由于其具有100%的原子利用率、 独特的化学结构及优异的催化活性等优点, 近年来在电化学催化和电能转换设备领域备受关注. 本文综合评述了单原子催化材料的设计理念、 合成方法和表征方法, 同时对其在氢电化学循环 (电解水制氢和氢燃料电池领域)的实际应用进行了系统介绍, 并对单原子催化材料的研究和应用前景进行了展望.     

多孔基体负载的碳纳米管复合膜制备及其气体渗透性能

采用改进的浮动催化法在多孔Al2O3基体上制备了垂直取向的碳纳米管阵列, 并用旋转喷涂法将聚苯乙烯填充于碳纳米管的空隙, 进一步将其制备成复合碳纳米管膜, 研究了H2和CO2单组分在碳纳米管复合膜中的渗透性能, 实验结果表明, H2/CO2的理想分离系数随着复合膜中碳管管径的减小而增大, 在管径较小的复合膜中, 气体渗透分离系数高于努森扩散限制, 达到6.25, 具有一定的分离效果. 两种气体在复合膜中的渗透率随着渗透温度的增加而减小.     

蒽醌法生产过氧化氢用新型氢化催化剂的制备

 采用水合肼液相还原法制备了负载型镍催化剂，对其催化蒽醌加氢反应的活性进行了考察，采用电感耦合等离子发射光谱、X射线衍射以及H2化学吸附等手段对催化剂进行了表征，并与用氢气还原法制备的催化剂进行了对比．结果表明，用水合肼还原制备的催化剂的Ni粒子较大，Ni分散度及H2吸附量较低，但其催化蒽醌氢化反应的活性高得多．     

取向碳纳米管制备方法及其应用进展*

碳纳米管有广阔的应用前景,但很多应用是以碳纳米管定向的取向排列为前提.本文全面介绍了制备取向碳纳米管的各种方法和研究进展,综合阐述了各种制备方法的特点,并初步讨论了制备取向生长碳纳米管各种方法的机理.最后,对取向碳纳米管的应用进行了展望,提出了碳纳米管应用的新思路.