Influence of Catalytic Poisons on the Selectivity of a Cobalt Catalyst for the Fischer–Tropsch Synthesis in Terms of the Theory of Astoichiometric Components of Catalytic Reactions

The effect of treatment of a freshly reduced cobalt catalyst with oxygen and ammonia on its properties in the Fischer–Tropsch synthesis was studied. It was shown that treatment with small amounts of catalytic poisons helped to increase the selectivity of the catalyst with respect to the formation of target products, linear C₅₊ hydrocarbons. The observed effect can be explained by partial blocking of the sites of direct CO hydrogenation to methane and modification of Lewis acid sites. The data obtained were consistent with the concept of the two-center surface model of Co catalysts for the Fischer–Tropsch synthesis and the theory of astoichiometric components of catalytic reactions.