TIME DEPENDENCE OF THE ACTIVITY AND SELECTIVITY OF A COBALT-CONTAINING CATALYST IN FISCHER–TROPSCH SYNTHESIS

Increasing the working time of the catalyst led to a change in the surface concentration of various intermediates. The activity of the catalyst decreased principally as a result of the decrease in the rate of methane formation. The probability of chain growth increases via alkyl intermediates and the contribution of secondary reactions in the process decreases. In this way the selectivity with respect to C5+ hydrocarbons increases, but the content of these products in the C2+ fraction decreases.