3643.     WELLER, S.  Kinetics of Carbiding and Hydrocarbon Synthesis With Cobalt Fischer-Tropsch Catalysts.  Jour. Am. Chem. Soc., vol. 69, 1947, pp. 2432-2436; Chem. abs., vol. 42, 1948, p. 1483.

        Rates of carbiding, of hydrogenation of carbide, and of hydrocarbon synthesis from CO-H₂ mixture shave been measured for a Co-ThO₂-kieselguhr catalyst (100:18:100) with the use of a circulating gas system.  The initial carbiding rate is comparable with the synthesis rate, but the steady rate of bulk carbiding is about 10 times lower.  The apparent activation energies for bulk carbiding and for the synthesis are 31 and 27 kcal. per mol., respectively.  Within the pressure range 8-45 cm. Hg, the pressure dependence of the carbiding rate can be expressed as Rate=kpⁿ, where n is 0.20-0.25.  Some of the implications of these results for the mechanism of the carbiding and synthesis are discussed.