采用溶胶 -凝胶、超临界干燥法制备了Al2 O3气凝胶负载钴催化剂 ,对该催化剂进行了物化性质表征和甲烷催化裂解反应的活性评价。分别考察了煅烧温度、反应温度对催化剂活性及生成碳纳米管形态的影响。煅烧后的Al2 O3气凝胶负载钴催化剂具有CoAl2 O4 尖晶石结构。Al2 O3气凝胶负载钴催化剂的积碳活性与还原后得到的金属催化剂的量成正比 ,随反应温度的升高 ,碳纳米管生长速率升高 ,催化剂失活速率同步加快 ,催化剂积碳活性下降。Al2 O3气凝胶负载钴催化剂在低温下具有较高的活性。在该催化剂上生长出的碳纳米管形态单一 ,均为弯曲、中空管状。碳纳米管内外壁光滑 ,管径均匀 ,随反应温度升高 ,碳纳米管直径变细。 62 5℃时 ,获得的碳纳米管直径在 8～ 1 0nm左右 The Al 2 O 3 aerogels supported cobalt catalysts were prepared by sol-gel and supercritical drying. The catalysts were characterized by their physico-chemical properties and methane catalytic cracking reactions. The effect of calcination temperature and reaction temperature on the catalytic activity and morphology of CNTs were investigated. The calcined Al 2 O 3 airgel supported cobalt catalyst has a CoAl 2 O 4 spinel structure. The carbon deposition activity of Al 2 O 3 aerogels supported cobalt catalyst is proportional to the amount of metal catalyst obtained after reduction. With the increase of reaction temperature, the growth rate of carbon nanotubes increases, the catalyst deactivation rate increases synchronously, and the catalyst carbon deposition activity decline. Al 2 O 3 airgel supported cobalt catalyst has high activity at low temperature. Carbon nanotubes grown on the catalyst had a single shape, both curved and hollow. Carbon nanotubes inside and outside the wall smooth, uniform diameter, with the reaction temperature, carbon nanotube diameter becomes thinner. 62 5 ℃, the diameter of carbon nanotubes obtained in about 8 ~ 10nm