Luo Tao, Gao Lisheng, Liu Jianwei, Chen Luyang, Shen Jianmin, Wang Licheng, Qian Yitai
Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemistry, University of Science and Technology of China, Hefei, 230026, People's Republic of China.
J Phys Chem B. 2005 Aug 18;109(32):15272-7. doi: 10.1021/jp051781z.
Olivary (olive-shaped) carbon particles (OCPs) with a diameter of approximately 1.5-2 mum at the middle and a length of approximately 3-4 mum were synthesized by pyrolysis of acetone with metallic zinc as the catalyst at 600 degrees C. The content of the OCPs in the product is related to the catalyst, the pyrolysis temperature, and the time of ultrasonic dispersion before pyrolysis. The content of the OCPs was over 90% of the product under the optimum condition. Mg, Ni, Fe, Cu, Zn, and Cd powder were used as catalysts in the experiments, respectively, in which the metallic zinc powder was outstanding in the pyrolyzing process; the metallic iron and cadmium powder also improved the formation of the olivary carbon particles; however, magnesium, nickel, and copper could not operate the catalysis. Through Fourier transform infrared spectroscopy analysis, the mechanism of the formation of the olivary carbon particles was suggested to be an indirectly catalytic and self-assemble process. By high-resolution transmission electron microscope observation, an interesting arrangement of crystal planes of carbon was found that (002) planes of graphite near the surface are vertical to the surface of the OCPs and not parallel as usual.
通过以金属锌为催化剂在600℃下热解丙酮合成了橄榄状（橄榄形）碳颗粒（OCPs），其在中部的直径约为1.5 - 2μm，长度约为3 - 4μm。产物中OCPs的含量与催化剂、热解温度以及热解前超声分散时间有关。在最佳条件下，OCPs的含量超过产物的90%。实验中分别使用了Mg、Ni、Fe、Cu、Zn和Cd粉末作为催化剂，其中金属锌粉在热解过程中表现突出；金属铁和镉粉也促进了橄榄状碳颗粒的形成；然而，镁、镍和铜不能起到催化作用。通过傅里叶变换红外光谱分析，推测橄榄状碳颗粒的形成机制是一个间接催化和自组装过程。通过高分辨率透射电子显微镜观察，发现了一种有趣的碳晶面排列，即靠近表面的石墨（002）面垂直于OCPs的表面，而不是通常那样平行。
