【摘要】 用X射线衍射仪、扫描电子显微镜和透射电子显微镜,研究了以瓷舟为载体、硝酸镍为原料、乙炔为碳源,在氨气中制备镍催化剂和纳米碳管时温度的影响,并讨论了氨气的作用。结果表明,以氨气还原硝酸镍获得镍催化剂时,最佳温度范围是700~800℃,此时催化剂的颗粒较细小且均匀,有利于纳米碳管的生长;此外,选用孔径比较细小均匀多孔的载体材料,有助于获得颗粒均匀细小的镍催化剂;在制备纳米碳管时,热分解氨得到的活性氢原子有利于维持催化剂的活性,抑制无定型碳的生成,从而促进纳米碳管生长。实验中纳米碳管的最佳制备温度为700~800℃,管径为10~25nm。更多还原

【Abstract】 Nickel catalysts and carbon nanotubes are synthesized by using porcelain boats as carriers, nickel nitrate as raw material, and acetylene mixed with ammonia as experimental gas. The effect of temperatures and the role of ammonia are studied with X ray diffractometer, scanning electronic microscope and transmission electronic microscope. The results show that the optimal temperatures are 700～800℃ for the ammonia deoxidizing nickel nitrate to obtain nickel catalyst, and the catalyst particles are small and homogeneous, which does good to the growth of carbon nanotubes. In addition, the porous materials with small and homogeneous aperture can be helpful to the formation of the small and homogeneous nickel catalysts, during the process of preparation for carbon nanotubes, the thermal decomposition of ammonia is beneficial to maintain the activity of catalyst, restraining the formation of impurities such as amorphous carbon, which facilitates the carbon nanotubes’ growth. The optimal temperatures of carbon nanotubes’ synthesis are 700～800℃ in the experiment and the diameters of carbon nanotubes are 10～25nm.更多还原