2009.     KUMMER, J. T., DEWITT, T. W., AND EMMETT, P. H.  Some Mechanism Studies on the Fischer-Tropsch Synthesis Using C14.  Jour. Am. Chem. Soc., vol. 70, 1948, pp. 3632-3643; Chem. Abs., vol. 43, 1949, p. 2081.

        Fischer-Tropsch synthesis experiments using C¹⁴ as a tracer show that the greater part of the product of synthesis is formed by some process other than by the reduction of carbide as an intermediate.  Only about 10% of the hydrocarbon product appears to have been formed through the carbide for Fe catalysts at or below 260° and for Co at 200°; at 300° the part of the reaction occurring through the carbide reduction mechanism seems to average about 16%.  The % formed through the adsorbed phase is not critically dependent on the H₂:CO ratio in the range 1:1-3:1, on the total pressure of the synthesis, within the limits 150-800 mm. pressure; or on the % Fe₂C initially present in the range 4-100%.  The exchange of the C in the gases, CH₄, CH₄H₁₀, butene-1, and C₂H₂, with an Fe carbide surface at 250° is found to be very low; CO exchange with the C in the carbide is only about 5% in 30 min. at 250°, but is as high as 29% in 7 min. at 322°.  The mechanism of carbiding has been investigated and has been shown to be complicated by the possibility of a nonuniformly reacting surface.  No completely satisfactory picture of the mechanism of carbiding has been formulated.