催化剂活性组成对纳米碳纤维产率和微结构的影响  

Effect of Active Metal Composition on the Yield and Microstructure of Carbon Nanofiber

作　　者：赵铁均[1] 朱贻安[1] 李平[1] DeChen 戴迎春[1] 袁渭康[1] AndersHolmen 

机构地区：[1]华东理工大学联合化学反应工程研究所国家重点反应工程实验室，上海200237 [2]挪威理工大学化工系，特隆赫姆N-7491，挪威

出　　处：《催化学报》2004年第10期829-833,共5页

基　　金：国家自然科学基金资助项目 ( 2 0 3 760 2 1) ;上海市重点实验室专项基金资助项目 ( 0 3 65 0 5 0 10 )

摘　　要：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 alumina supported nickel/iron catalysts with different active metal compositions were prepared by the deposition-precipitation method, and the carbon nanofiber (CNF) was catalyticly grown on the above catalysts at 600 ℃ by using CO/H 2 mixture as a carbon source. The catalytic activity was stable after 36 hours on stream, and the presence of Fe in the catalyst promoted the growth of CNF. The formed CNF diameter distribution was narrow in the range of 20～50 nm. The HRTEM result showed that the angle between the CNF axis and the graphite layer increased with the increase of Fe content. The TPO result indicated that the graphitization degree of the CNF depended on the active metal composition. The yield and microstructure of CNF changed with the active metal composition, which was attributed to the surface reaction between CO and active metal (alloy) together with the carbon diffusion mode on/in the metal particle.

关 键 词：纳米碳纤维 催化生长 微结构 活性金属组成 沉积-沉淀法 

分 类 号：O643[理学—物理化学]