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采用沉积 沉淀法制备了活性组成可控的镍铁系列催化剂 ,以CO/H2 为碳源 ,在 6 0 0℃下进行了纳米碳纤维的催化生长 ,考察了催化剂活性组成变化对纳米碳纤维产率和微结构的影响 .结果表明 ,镍铁系列催化剂具有较好的催化活性 ,在反应36h内没有失活 ,催化剂中Fe的存在有利于提高纳米碳纤维的产率 .表征结果表明 ,纳米碳纤维的直径分布较为均匀 ,在 2 0～ 5 0nm之间 ,比表面积为 130～ 2 0 0m2 / g;纳米碳纤维中石墨层与轴之间夹角随催化剂中Fe含量的增大而增大 ;TPO结果表明 ,Fe的存在提高了纳米碳纤维的石墨化程度 .结合纳米碳纤维的生长机理 ,认为活性组成的变化影响了CO与催化剂表面的反应和碳在金属中的扩散 ,进而影响纳米碳纤维的产率和微结构 .
A series of Ni-Fe catalysts with controlled active composition were prepared by deposition precipitation method. The catalytic growth of nanocarbon fibers was carried out at 600 ℃ with CO / H2 as carbon source. The effects of the catalyst composition on the yield of nanofibers, The results show that the Ni-Fe series catalyst has good catalytic activity and does not deactivate within 36h, and the existence of Fe in the catalyst is beneficial to improve the yield of the nanofibrous carbon fiber.The characterization results show that the nanocarbon fiber diameter distribution And the specific surface area is 130 ~ 200m2 / g. The angle between the graphite layer and the axis of nanofibers increases with the increase of Fe content in the catalyst. The results of TPO show that, The existence of Fe improves the graphitization degree of nanofibers.Based on the growth mechanism of nanofibers, it is considered that the change of the active composition affects the reaction between CO and the catalyst surface and the diffusion of carbon in the metal, thus affecting the yield and microstructure of nanofibers .