Cobalt and iron supported on carbon nanofibers as catalysts for Fischer-Tropsch synthesis
Résumé
Cobalt and/or iron supported on carbon nanofibers were prepared and used as monometallic or bimetallic catalysts for Fischer-Tropsch synthesis at 523 K and 20 bar. Catalysts were characterized by ICP, N-2 adsorption-desorption, TPR, XRD and XPS. Characterization results revealed that cobalt and iron had a synergetic effect: cobalt particles were better dispersed in presence of iron, and the latter was reduced to Fe in a higher extent due to the presence of the former. Catalytic results revealed that cobalt content played an important role in the catalytic conversion of CO. This way, the higher the content in cobalt, the higher the CO conversions were observed. Thus, sample 15Co/CNF presented the highest CO conversion. However, the presence of iron in bimetallic catalysts avoided an excessive production of CH4. The bimetallic sample with the highest Co loading (10Co5Fe/CNF) was the most active catalyst for the FTS reaction, because it led to the highest yield of longchained hydrocarbons. (C) 2014 Elsevier B.V. All rights reserved.