3361.     ---------------.  [TEICHNER, S.]  [Analogies of Texture Between Activated Montmorillonites and Certain Catalysts.]  Jour. chim. phys., vol. 47, 1950, pp. 244-252; Chem. Abs., vol. 44, 1950, p. 7635.

        Adsorption results are summarized.  Adsorption studies with N2 and hydrocarbons were made of 6 Fischer-Tropsch catalysts.  The loss in weight, the density as determined by He, and the surface areas are given for the following thermal treatments:  Desorption under vacuum at 20, desorption under vacuum at 150, and reduction at 450 and desorption under vacuum at 150.  In 4 cases, the reduced catalysts exhibited much greater surface areas than the catalysts subjected only to a vacuum treatment at 20 or 150.  Results are tabulated for the surface area of the support, and the surface area of the catalysts impregnated on these supports before and after reduction for kieselguhr subjected to the following treatments:  Treated with mineral acids, untreated support, treated with 5% Na2CO3.  The surface area of the catalysts was greater than those of the supports.  The initial surface areas of the support did not determine the surface area of the catalyst after reduction.  The difference between the total adsorption of N2 and CO at -195 was utilized to determine the fraction of metal exposed at the surface.  The results are given for 4 catalysts.  The fraction of surface covered by metal atoms ranged 0.35-0.65.