Influence of the composition and preparation method of KFeCo/γ-AlO catalysts on their catalytic behaviour in the hydrocarbons synthesis from CO

A series of iron-containing catalysts supported on γ-AlO and modified with potassium and cobalt were studied in the reaction of hydrocarbon synthesis from CO. Samples from different series differed in the deposition method and component ratios. When preparing catalysts modified with cobalt and potassium by co-impregnation in excess of impregnation solution, an uneven distribution of cobalt and iron cations was observed on the catalyst surface. Applying iron and modifiers by consecutive impregnation in excess of impregnation solution with intermediate heat treatment in air allows for a uniform distribution of cobalt and iron cations. This leads to a significant increase in selectivity for C hydrocarbons formation and a decrease in methane selectivity. For catalysts prepared by the consecutive impregnation method, the optimal cobalt-to-iron ratio was found to be / ≈ 0.35–0.45, along with an iron active component content of ω ≈ 4%.