催化剂对纳米聚团床法制备的纳米碳材料形貌的影响

 在纳米聚团床中用催化化学气相沉积法批量制备了碳纳米管，研\r\n究了过渡金属催化剂对碳纳米管形貌和产量的影响．实验结果表明，含\r\n铁催化剂的活性较低，产率较低，但产品质量较好；含镍催化剂的活性\r\n较高，产率较高，但产品质量较差；在钴催化剂作用下发现了一种新型\r\n的针状纳米碳材料．用含载体较少的铁催化剂可以得到纯度较高且微观\r\n结构较好的碳纳米管，但产率较低；不含任何载体的纯镍催化剂则不能\r\n得到碳纳米管．适宜的催化剂组成、催化剂活性点的均匀分布和裂解速\r\n度的控制等构成了纳米聚团床大批量制备碳纳米管技术的关键．

Effect of Catalyst on Morphology of Carbon Nano-materials Prepared in a Nano-agglomerate Bed

Carbon nanotubes (CNTs) were prepared in batch process by catalytic chemical vapor deposition (CCVD) using a nano agglomerate bed. Effects of transition metal catalysts on morphology and output of CNTs were studied. The experimental results showed that better quality of CNTs can be achieved at low carbon yield with Fe catalysts; with Ni catalysts, the carbon yield is much higher but the quality of CNTs produced is worse; with Co catalyst, a novel carbon nano material with needle shape which has not yet been reported is discovered. Effects of catalyst supports on preparation of CNTs in the nano agglomerate bed is also very important. CNTs with better micro structure and higher purity can be achieved using Fe catalysts with few supports, but their activity is not enough high and the carbon yield is low. CNTs can not be produced using pure Ni nanoparticle catalyst without any support. According to these experimental results, it is clear that suitable catalyst components, even dispersion of active centers and proper pyrolysis rate are key factors for preparation of CNTs in batch process in the nano agglomerate bed.