Effect of Topochemical Processes in the Synthesis of FeK/C Catalysts on Their Activity and Selectivity in the Fischer-Tropsch Synthesis

Iron-containing catalysts promoted with potassium supported on a carbon carrier were prepared by changing the sequence of the introduction of components (iron and potassium) into the carrier (activated carbon) using an impregnation method. After calcination, the catalysts contained hematite and magnetite; in this case, the particle sizes of iron oxides depended on the sequence of the introduction of a potassium promoter. A minimum particle size was observed upon the subsequent introduction of initially potassium from nitrate and then iron. The activation of all of the catalysts in a flow of CO/H-2 resulted in the formation of Hagg carbide (Fe5C2). It was shown that the catalyst with the smallest carbide particle size was the most active in the hydrogenation of CO.