铁基催化剂裂解乙烯制备高纯度碳纳米管  

Preparation of High Purity Carbon Nano-Tubes from Ethylene Decomposition over Nanosized Iron-Based Catalysts

作　　者：凌晨[1] 骞伟中[1] 陈理[1] 刘唐[1] 魏飞[1] 汪展文[1] 

机构地区：[1]清华大学化工系北京市绿色反应工程与工艺重点实验室,北京100084

出　　处：《石油化工》2005年第6期569-572,共4页Petrochemical Technology

基　　金：国家自然科学基金项目(2036020);中国石油化工股份有限公司科学技术研究开发项目(X503022)

摘　　要：研究了纳米Fe/Al2O3催化剂在流化床中裂解乙烯制备碳纳米管的情况.催化剂上铁晶粒的尺寸随铁负载量的增加呈线性增大.碳产品的生长倍率先随着铁负载量的增加而增大;在铁负载量(质量分数)为33%时达到最大值;然后逐渐减小.在铁负载量相同时,催化剂上的铁晶粒尺寸随还原温度和反应温度的升高而增大.较低的反应温度(773 K)对提高碳产品的生长倍率及抑制无定形碳的形成有利.在铁负载量33%、还原温度773 K的催化剂作用下,反应温度为773 K时,可得到生长倍率(以每克催化剂生成的碳产品的质量计)为75g/g、平均直径为10～15 nm的碳纳米管,产品中几乎不含无定形碳及被碳包覆的铁晶粒.Carbon nanotubes (CNTs) were prepared from ethylene decomposition on nanosized Fe/Al2O3 catalysts (iron loading of 16%-66%) in fluidized bed reactor. The size of iron crystallites on catalyst increased linearly with iron loading. Yield of CNTs increased first with iron loading on catalyst, and attained maximum when iron loading was 33%, then went downward with further increasing of iron loading. When iron loading kept unchanged, size of iron crystallites on catalyst significantly enlarged with reduction temperature and reaction temperature. Relatively low temperature (773 K) of which advantaged increase of CNTs yield and inhibition of amorphous carbon formation. Yield of CNTs could mount 75 g/g catalyst at reaction temperature 773 K on catalyst prepared at that temperature with iron loading of 33%. Average diameter of the CNTs obtained was 10-15 nm. Product nearly did not contain amorphous carbon and carbon-encapsulated iron particles.

关 键 词：碳纳米管 纳米铁基催化剂 乙烯 化学气相沉积法 流化床 

分 类 号：TQ428.8[化学工程]