Co^2＋含量对CoAl-LDHs焙烧产物结构、组成及其生长碳纳米管的影响  

Influence of Cobalt Content on Structure and Composition of Calcined Co-Al Layered Double Hydroxides and Catalytic Property for the Carbon Nanotubes Formation

作　　者：Halidou I.Hima 项顼[1] 张璐[1] 李峰[1] David G.Evans 

机构地区：[1]北京化工大学化工资源有效利用国家重点实验室,北京100029

出　　处：《无机化学学报》2008年第6期886-891,共6页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.20631040,20601002);高等学校创新引智计划(B07004)资助项目

摘　　要：采用成核晶化隔离法将Co2+引入层状双金属氢氧化物(LDHs),得到了含不同Co2+/Al3+物质的量的比为1∶1,2∶1,3∶1的二元钴铝碳酸根型LDHs(CoAl-LDHs)。通过X射线衍射(XRD)、透射电镜(TEM)、扫描电镜-能量散射谱(SEM-EDS)、拉曼光谱(Raman)、程序升温还原(TPR)及X射线光电子能谱(XPS)等方法对CoAl-LDHs焙烧产物的结构、组成及其化学气相沉积(CCVD)催化生长多壁碳纳米管(CNTs)进行了研究。结果表明:CoAl-LDHs前体中钴的含量可以明显改变焙烧产物的组成分布和还原性能,并最终影响CNTs的生长,其中以nCo2+/nAl3+比为2/1的LDHs作为催化剂前体可以得到管径均匀和石墨化程度高的CNTs,这与还原得到的纳米活性Co颗粒均匀分散有关。Multi-walled carbon nanotubes （CNTs） were prepared via catalytic chemical vapor deposition （CCVD） of acetylene over a series of Co-containing mixed metal oxides obtained by calcination of layered double hydroxides （LDHs） precursors with Co^2＋/Al^3＋ molar ratios ranging from 1∶1 to 3∶1. The materials were characterized by means of XRD, TPR, XPS, SEM-EDS, TEM and Raman spectroscopy. The results indicate that the cobalt content in precursor has a significant effect on the structure and composition of calcined LDHs and thus the growth of CNTs. Furthermore, it is found that the precursor with the Co^2＋/Al^3＋ molar ratio of 2.0 gives rise to much more uniform CNTs with higher graphitization due to the more uniform dispersion of active metallic Co nanoparticles obtained by reduction of calcined products.

关 键 词：层状双金属氢氧化物 碳纳米管 催化 钴 

分 类 号：O631[理学—高分子化学]