2773.     RAPOPORT, I. B., AND LANG, A.  [Genesis of Catalyst Skeletons.]  Jour. Appl. Chem. (U.S.S.R.), vol. 11, 1938, pp. 1056-1062 (in French, p. 1063); Foreign Petrol. Technol., vol. 7, 1939, pp. 13-26; Chem. Abs., vol. 33, 1939, p. 4115.

        Properties of catalyst skeletons, which were obtained by the treatment of alloy (Ni-Co-Al or Ni-Al) with an alkali to remove most of Al, were investigated.  The catalyst skeletons are more stable against poisoning with S-containing organic compounds than the precipitated catalysts (oxides).  The hydrogenation of caprylene, octyl alcohol, cyclopentanone and 1, 3, 4-xylenol in a current of H₂ at 190°-195° disclosed that the Ni-Co-Al catalyst skeleton is a very active hydrogenation catalyst.  The dehydrogenation of cyclohexane and methylcyclohexane over the above catalyst proceeded very effectively at 180°-200°, with pressure or without it.  The best products were obtained at 240°-260° but the reaction, in this case, was accompanied by a decomposition reaction.  At temperature above 260° (280°-320°), the surface of the catalyst was gradually covered with a C film and the catalyst completely lost its activity.  The catalyst cannot be reactivated in the usual manner.  The loss of activity is explained by the recrystallation of the crystal lattice of the catalyst skeleton at high temperature.  Therefore, the isomerization reaction in the presence of the catalyst skeleton would not proceed to a great extent because: (1) The catalyst rapidly loses its activity at 270°-280° and (2) at this temperature the main reaction is the decomposition reaction.  Thus, the catalyst skeletons prepared from Ni-Co-Al and Ni-Al alloys are similar to the precipitated catalysts (oxides) in respect to hydrogenation, dehydrogenation, and isomerization reactions, but the first catalysts are less affected by S-containing organic compounds.