An Efficient Catalyst for the Large Scale Production of Multi-Walled Carbon Nanotubes

The main objective of this work is to design an efficient catalyst for the synthesis of multiwalled carbon nanotubes (MWNTs) in our scalable, high quality with gram amount synthesis. The catalysts with composition of Fe, Mo, and MgO in the molar ratios 1:0.5:13, 1:1:13, and 1:1:50 were prepared by combustion method. The high acetylene conversion and carbon yield of chemical vapor deposition (CVD) reaction suggest the formation of MWNTs by 1:1:50 molar ratio catalysts under pyrolysis of the pure C2H2 gas with the flow rate about 60 mL/min at 80o degrees C for 30 min. The catalysts and the resulting CNT samples were analyzed by XRD, TGA, FT-Raman, SEM, and TEM to establish a relation between catalyst design and MWNT yield. Raman results indicate that CNTs are in multiwarled structure, since no single-walled characteristic features appear in the 200-400 cm(-1) region. We give evidence that increased carbon conversion, carbon yields and % purity of more than 65%, 1000%, and 9996, respectively, with respect to our catalysts are directly related to ratio between Fe Mo and MgO. One g of acetylene containing 0.9231 g of carbon would enter the reaction chamber, which is responsible for the 1.96, 1.9842, and 2.2356 g of the carbon deposition per 200 mg of catalyst A, B, and C respectively.