Synthesis Of Carbon Nanotubes And Application In Catalytic Hydrogenation

Carbon nanotubes are a kind of novel function materials with a 2-D sheet of tubular structure. Due to their special structure, nanotubes offer strong quantum effect and unique physics chemical properties, thus they are looked upon as promising candidates in a lot of applications, such as catalysis, multi materials, deposited materials, miniaturized electronic and etc. Nowadays, Various methods, such as arc-discharge, laser ablation, catalytic chemical vapor deposition(CVD) and etc, have been successful in producing CNTs materials, but low yield and production in miniature are the main disadvantages for the former two methods, and the CVD method becomes the mainly production method of CNTs for it's simple reactor, low cost, controlled reaction and high yied.Prepare catalyst by coprecipitation method and produce CNTs by CVD. This thesis compared the novel catalyst's capability advantages over the traditional catalyst; optimized processes for synthesis of CNTs; studyed the effects of composition ration, plasma treatment, ultrasonic treatment,additional composition on the CNTs growth in order to improve the yied. On the conclusion, because of the special synthesis method, the novel catalyst made the grown CNTs show many excellent characters compared with the traditional catalyst, such as uniform in tube diameter, pure product, high yield and etc. The yield of CNTs remarkably increased to 4.61g.g_cat.^-1.h^-1 over novel catalyst from 0.74g.g_cat.^-1.h^-1 over traditional catalyst. Furthermore, plasma treatment, ultrasonic treatment, additional composition and etc were helepful for the yield, the highest yield of CNTs attained was 5.93g.g_cat.^-1.h^-1. This study also confirmed the theory that the CNT diameter depends on the size of the catalyst nanoparticles. The catalytic performance of Co-B/CNTs was investigated by using CMA hydrogenation as the probe reaction. Compared with Co-B/SiO₂, Co-B/γ-Al₂O₃, the Co-B/CNTs showed the highest cinnamaldehyde(CMA) conversion (42.4%) and cinnamyl alcohol (CMO) selectivity (94.0%). The CMA conversion was 2.6 and 2.1 times over Co-B/SiO₂ and Co-B/γ-Al₂O₃, respectively.