47.    ANDERSON, R. B., HALL, W. K., AND HOFER, L. J. E.  Studies of the Fischer-Tropsch Synthesis.  IV.  Properties of Reduced Cobalt Catalysts.  Jour. Am. Chem. Soc., vol. 70, 1948, pp. 2465-2472; Chem. Abs., vol. 42, 1948, p. 8058.

               Reduced Co : ThO₂ : MgO : kieselguhr (100 : 6 : 12 : 200) and Co : ThO₂ : kieselguhr (100 : 18 : 100) and similar preparations with one or more of the components omitted have been studied by N surface areas and CO chemisorptions at –195°, Hg and He densities, and X-ray diffraction.  The experimental data show that the surface areas of all the catalysts studied decreased on reduction.  The promoters were found to prevent excessive decreases; powdered MgO appears to be the most effective and ThO₂ the least.  Kieselguhr as a carrier was somewhat effective in preventing the decrease of surface area and in increasing the pore volumes on reduction of all the catalysts.  With unpromoted and unsupported Co large changes occurred in both surface area and bulk volume.  The most important function of the kieselguhr was to prevent the decrease in bulk volume of the catalyst on reduction and at the same time inhibit sintering of the surface.  The CO chemisorption studies showed that an appreciable fraction of the catalyst surface was occupied by promoter.  The X-ray diffraction data were in qualitative agreement with the surface-area determinations but in addition indicated that the Co in supported and promoted catalysts had an anomalous structure.