Ni助剂FeMnK/SiO_2费托合成催化剂的结构性质及还原碳化行为研究

Structural properties and reduction behavior of Ni promoted FeMnK/SiO_2 catalysts for Fischer-Tropsch synthesis

研究了N i助剂对共沉淀型FeMnK/S iO2催化剂的结构性质和还原炭化行为的影响。结果表明,添加少量N i助剂提高了催化剂的比表面积,降低了平均孔径,促进了催化剂中铁氧化物的分散。在H2-TPR中,N i助剂降低了催化剂的还原温度;在CO-TPR中,N i助剂使催化剂的还原和炭化峰前移,提高了氧的移除速率,增加了碳的引入量;在合成气等温还原中,N i助剂提高了催化剂的活化速率,在相同的还原时间内可获得更高的F-T合成反应活性。

Ni promoter was introduced into the co-precipitated FeMnK/SiO2 Fischer-Tropsch synthesis catalysts. The effects of Ni on catalyst structural properties, reduction and carburization behaviors were studied by N2 physical adsorption, XRD, Moessbauer spectroscopy, temperature programmed reduction （TPR） in H2 and CO, and isothermal reduction in syngas. The results indicate that Ni promoter increases the BET surface areas of catalysts and is favorable to the formation of smaller crystallite particles. H2-TPR results show that Ni decreases the reduction temperature of catalysts, and CO-TPR results show that Ni facilitates the oxygen removal and increases the carbon introduction content. These effects contribute to a significant improvement of the reduction and carburization behaviors of catalysts in syngas, and the promotion effect increases with the Ni loading content.