DYNAMICS OF THE FISCHER-TROPSCH SYNTHESIS OVER A SUPPORTED COBALT CATALYST

Step-change experiments between H-2, CO, and syngas mixtures with time resolution of ca. 0.3 s were undertaken to critically test mechanisms proposed in the literature for the Fischer-Tropsch synthesis. A silic a-supported cobalt catalyst was used. Results suggest C2+ olefins and branched paraffins form from a carbon deposit on the catalyst surface. Two pathways appear to exist for methane formation. The first of thes e is from the carbon deposit through direct hydrogenation and through hydrogenolysis of the long-chain materials formed. The second pathway is hydrogenation of strongly adsorbed CO.