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采用气相催化沉积法催化合成纳米碳管,比较了不同金属氧化物和金属负载型沸石催化剂以及不同分子筛载体对合成纳米碳管的影响,并用TEM,XRD表征其形貌和结晶度,用DTA-TG考察了纳米碳管的热稳定性.实验结果表明纳米碳管的形成除了与金属种类有关外,还直接与催化剂的颗粒大小和分散状态有关,粒径在20nm左右的不规则形状的纳米粒子是形成纳米碳管的活性组分,非负载和负载型的催化剂均表明活性组分的粒径与纳米碳管的管径有一定的对应关系.化学提纯后能得到高纯度的纳米碳管;其管壁具有较好的石墨化结构,在空气中的热稳定性大于400℃,而在氮气中能维持到1200℃以上.
Carbon nanotubes were synthesized by gas-phase catalytic deposition. The effects of different metal oxides, metal-supported zeolites and different molecular sieve supports on the synthesis of carbon nanotubes were compared. The morphology and crystallinity of the carbon nanotubes were characterized by TEM and XRD. TG investigated the thermal stability of carbon nanotubes.The experimental results show that the formation of carbon nanotubes in addition to the type of metal, but also directly with the catalyst particle size and dispersion state, particle size of about 20nm irregularly shaped nanoparticles Is the active component of the formation of carbon nanotubes, both supported and unsupported catalysts indicate that the particle size of the active component has a certain correspondence with the diameter of the carbon nanotubes, and the carbon nanotubes with high purity can be obtained after chemical purification; The tube wall has a good graphitization structure, the thermal stability in the air is greater than 400 ° C, and in nitrogen can be maintained above 1200 ° C.