摘要
采用固-固研磨焙烧方法制备了分散型的Nb_2O_5/ZSM-48催化剂母体,XRD和SEM鉴定结果表明,在一定负载量内,Nb_2O_5可均匀地分散于ZSM-48沸石载体表面。由于Nb_2O_5的引入,改变了载体表面性质,同时也改善了Fe-K-Nb_2O_5/ZSM-48催化剂的还原及对CO和H_2的吸附性能,其结果促进了一氧化碳加氢反应的进行和低碳烯烃反应产物的生成,同时提高了催化剂的稳定性。
Crystalline Nb_2O_5 and zeolite ZSM-48 carrier were mixed thoroughly and the mixture(Nb_2O_5, 6.25w%) was calcined at 540℃ (m.p. of Nb_2O_5 is 1460℃) for 9 hours. The X-ray diffraction peaks of Nb_2O_5 disappeared. It indicated that the metal oxide was spontaneously dispersed on the surface of the zeolite. The results of SEM confirmed the dispersion. The interaction of Nb_2O_5 and ZSM-48 promoted the spontaneous dispersion of Nb_2O_5 and influenced the characteristics of the support and the catalyst K-Fe/Nb_2O_5/ZSM-48. When the quantify of Nb_2O_5 on the support is between 1.25-2.50w%, the catalysts have good catalytic activity and selectivity for CO hydrogenation to light olefins. The addition of Nb_2O_5 onto the support also increases the stability of the catalysts.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
1992年第2期188-193,共6页
Journal of Fuel Chemistry and Technology
关键词
催化剂
助剂效应
五氧化二铌
沸石
solid-solid adsorption
zeolite supported catalyst
CO hydrogenation
assistant effect
