| 催化剂载体对CVD法制备碳纳米管的影响 |
| Effects of Catalyst Supporting in the Synthesis of Carbon Nanotubes using CVD Method |
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| 摘要: 用DTA、TEM和XRD方法研究了碳氢化合物催化裂解制备碳纳米管(CNTs)反应中催化剂载体的影响。实验结果表明:当以金属Co作为活性组分时,对于催化剂Co/Al2O3,在最佳反应温度(650℃)条件下,碳纳米管粗产品的产率为457g/100g·cat,明显高于以Co/SiO2作载体时的产率131g/100g·cat,且碳纳米管直径小,直径分布范围窄(10nm～20nm)。但在空气气氛中的DTA结果表明,在催化剂Co/SiO2上生成的碳纳米管的抗氧化能力较在催化剂Co/Al2O3上生成的碳纳米管强。通过TEM和XRD方法进一步研究发现:反应过程中,催化剂Co/Al2O3中的Co微晶粒度随反应温度升高(从650℃到750℃)而增大(从15.8nm到16.7nm)的速率小于催化剂Co/SiO2中的Co微晶粒度随反应温度升高而增大(从11.0nm到13.4nm)的速率;相应地,在催化剂Co/Al2O3上生成的碳纳米管的(外)直径随反应温度升高而增大的速率(从10～20nm到20～25nm)亦小于在催化剂Co/SiO2上生成的碳纳米管的(外)直径随反应温度升高而增大的速率(从10～30nm到30～50nm)。 |
| 关键词: 碳纳米管 催化剂载体 三氧化二铝 CVD方法 |
| 基金项目: |
| Abstract: The influence of catalyst support on the syntheses of carbon nanotubes (CNTs) through hydrocarbon (C2H2) catalytic cracking has been studied by DTA, TEM and XRD methods. Experiment results show that, using tran-sition metal Co as the active component of the catalyst and at the optimum reaction temperature (650℃), the yield of carbon nanotubes with the outer diameter of 10nm～20nm produced on catalyst Co/Al2O3 is 457g/100g·cat and with the outer diameter of 10nm～30nm produced on catalyst Co/SiO2 is only 131g/100g·cat. However, the DTA experiments under air atmosphere show that the oxidation resistance of carbon nanotubes produced on catalyst Co/SiO2 is stronger than that produced on catalyst Co/Al2O3. Through TEM and XRD methods, the further study in-dicates that with increase in the reaction temperature (from 650℃ to 750℃), the average grain size of supported Co crystallite is growing up, from 15.8nm to 16.7nm for Al2O3 supporter and 11.0nm to 13.4nm for SiO2 supporter respectively. Moreover, this growing rate is relatively lower on Al2O3 than that on SiO2. Accordingly, with the increase of temperature, the growing rate of the outer diameter (from 10～20nm to 20～25nm) of the carbon nanotubles generated on catalyst Co/Al2O3 is lower than that (from 10～30nm to 30～50nm) generated on catalyst Co/SiO2. |
| Keywords: carbon nanotubes catalyst support aluminum oxide CVD method |
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| 吕德义,徐铸德,徐丽萍,葛忠华.催化剂载体对CVD法制备碳纳米管的影响[J].无机化学学报,2002,18(5):475-480. |
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