用浸渍法、化学气相沉积法(MOCVD)、乙二醇液相还原法制备碳纳米管负载钴催化剂, 以1-辛烯的氢甲酰化反应为探针反应, 对比研究了所制得的Co/CNTs催化剂的催化性能, 并用XRD和TEM等技术研究了催化剂的粒子大小及粒径分布, 考察了1-辛烯的氢甲酰化反应性能与催化剂粒径大小的关系.发现用MOCVD法制备的Co/CNTs催化剂的平均粒径最小, 其平均粒径为7.5 nm左右且分布均匀; 该催化剂在1-辛烯的氢甲酰化反应中具有最高的催化活性和C9-醛的选择性.
Carbon nanotube-supported cobalt catalysts were prepared by using three techniques including impregnation method (IP), metal organic chemical vapor deposition method (MOCVD) and modified ethylene glycol method (EG). The size distribution of Co metal particles on Co/CNTs was studied with XRD and TEM. It was found that the Co/CNT catalysts prepared by MOCVD had high and homogeneous dispersion of spherical Co metal particles with a narrow particle-size distribution in the range of 5-10 nm centering around 7.5 nm, which is consistent with the calculated value 7.1 nm obtained by Scherrer formula from the XRD data. For the hydroformylation of 1-octene, the Co/CNT catalysts prepared by MOCVD were superior to those prepared by other methods and showed significantly higher activity and regioselectivity. The excellent catalytic performance could be attributed to homogeneous distribution and small size of cobalt metal particles.