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通过XRD、DTA和TEM方法 ,研究了不同温度下催化剂活性组分Co和Ni对化学气相沉积(CVD)法制备碳纳米管的影响。结果表明 ,在最佳反应温度 ( 65 0℃ )下 ,碳纳米管在催化剂Co Al2 O3 上的产率为 45 7g 1 0 0g·cat,高于在Ni Al2 O3 上的产率 3 42g 1 0 0g·cat。XRD分析表明 ,相对于催化剂Co Al2 O3 ,在Ni Al2 O3 上制备的碳纳米管石墨化程度更高。当合成温度从 65 0℃增加到 75 0℃时 ,在催化剂Co Al2 O3 和Ni Al2 O3 上生成的多壁碳纳米管的 ( 0 0 2 )晶面的层间距分别从 3 45 和 3 42 减小到 3 3 9 和3 3 7 。进一步分析发现 ,在焙烧或催化反应过程中 ,Co、Ni与γ Al2 O3 之间存在相互作用且生成了新相物质 ,其衍射峰分别为 2θ=5 1 5 6°和 2θ=5 1 97°
The effects of Co and Ni, which are the active components of catalysts, on the preparation of carbon nanotubes by chemical vapor deposition (CVD) were investigated by XRD, DTA and TEM. The results show that at the optimum reaction temperature (65 0 ℃), the yield of carbon nanotubes on the catalyst Co Al 2 O 3 is 45 7 g 100 g · cat, higher than that on Ni Al 2 O 3 3 42 g 10 0g · cat. XRD analysis showed that the carbon nanotubes prepared on NiAl2O3 were more graphitized than the catalyst CoAl2O3. When the synthesis temperature was increased from 65 0 ℃ to 75 0 ℃, the interlayer spacing of the (0 0 2) planes of the multi-walled carbon nanotubes formed on the catalysts Co Al 2 O 3 and Ni Al 2 O 3 decreased from 3 45 and 3 42, respectively Small to 3 3 9 and 3 3 7. Further analysis showed that during the calcination or catalysis, Co, Ni interacted with γ Al 2 O 3 and formed new phases with diffraction peaks of 2θ = 5 1 5 6 ° and 2θ = 5 1 97 °, respectively