膨润土化学改性及其催化生长碳纳米管研究

Study on Titanate Modification of Bentonite & Its Catalytic Synthesis of Carbon Nanotube

以化学改性膨润土为催化剂,利用化学气相沉积法催化裂解CH4,在高温条件下成功地制备了碳纳米管,并用透射电镜对其形貌与结构特征进行了表征。结果表明,所得产物形状弯曲,管径为15～20nm、长度达微米级的均匀碳纳米管;膨润土释放的金属铁起到了催化CH4的作用,在800℃条件下生长的碳纳米管质量最好、产率最高,若催化反应温度过高则会降低产品的质量,催化温度低于700℃时不能用来制备碳纳米管。与传统的过渡金属催化剂相比,这种矿物催化剂原料成本低廉,制备工艺简单,有利于碳纳米管的工业化生产。

Titanate-modified bentonite could catalyze acetylene into synthesis carbon nanotubes at high temperature by thermal chemical vapor deposition.The element iron contained in bentonite acts as the catalytic metal of nanotubes.A conclusion was drawn that the quality and quantity of carbon nanotubes were best and largest respectively at 800℃.If the temperature is higher than 900℃,the quality of nanotubes would be bad.The catalytic capacity of modified bentonite would disappear below 700℃.The catalyst is cheaper and its treatment is simpler than traditional metal catalyst, which may accelerate industrial synthesis of carbon nanotubes.