Effects of the Different Supports on the Activity and Selectivity of Iron-Cobalt Bimetallic Catalyst for Fischer-Tropsch Synthesis

摘要

Silica, alumina, and activated carbon supported iron-cobalt catalysts were prepared by incipient wetness impregnation. These catalysts have been characterized by BET, X-ray diffraction (XRD), and temperature-programmed reduction (TPR). Activity and selectivity of iron-cobalt supported on different carriers for CO hydrogenation were studied under the conditions of 1.5 MPa, 493 K, 630 h~(-1), and H_2/CO ratio of 1.6. The results indicate that the activity, C_4 olefin/(C_4 olefin+C_4 paraffin) ratio, and C_5 olefin/(C_5 olefin+C_5 paraffin) decrease in the order of Fe-Co/SiO_2, Fe-Co/AC1, Fe-Co/Al_2O_3 and Fe-Co/AC2. The activity of Fe-Co/SiO_2 reached a maximum. The results of TPR show that the Fe-Co/SiO_2 catalyst is to some extent different. XRD patterns show that the Fe-Co/SiO_2 catalyst differs significantly from the others; it has two diffraction peaks. The active spinel phase is correlated with the supports.