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Literature Abstracts

 1705.    KAZANSKIĬ, B. A., PLATÉ, A. F., BULANOVA, T. F., AND ZELINSKIĬ, N. D.  [Contact Cyclization of Paraffinic Hydrocarbons. Catalysts Containing Vanadium Pentoxide and Thorium Dioxide.]  Compt. Rend. Acad. Sci. U.R.S.S., vol. 27, 1940, pp. 658-663; Chem. Abs., vol. 35, 1941, p. 1386.

       When a synthin fraction, boiling at 83°-138°, was passed over V₂O₃ at approximately 500°, NH₄VO₃ (preliminary heating to 500° in N₂ at 500° or Al₂O₃ at 450°-555°, there was virtually no formation of aromatic hydrocarbons. Alumina with 5-10% of V₂O₅ at 475°-500° catalyzes the formation of aromatic hydrocarbons from synthin fractions, which boil at 83°-138° and 162°-205°, respectively, but gradually loses its activity, becoming covered with C.  The catalyst readily regains its original activity by heating in a current of air.  Cr₂O₃ with 10% V₂O₅ at 450°-470° showed considerable catalytic activity but rapidly lost its activity.  Parby kieselguhr with 10% V₂O₅ did not catalyze the formation of aromatic hydrocarbons from a synthin fraction boiling 83°-138°.   Alumina with 10% ThO₂ catalyzed the formation of aromatic hydrocarbons from the same synthin fraction.  The catalytic activity of alumina with 10% ThO₂ at 500° for the formation of aromatic hydrocarbons from the same synthin fraction increased slowly and then slowly decreased; the catalyst can be regenerated by heating with air.  Alumina with 10% V₂O₅ and 2% ThO₂ at 475°-500° acted in the same manner as alumina with 10% V₂O₅.  Activated charcoal with 10% ThO₂ at 450°-470° catalyzed considerably the formation of aromatic hydrocarbons from the synthin fraction, but the catalyst declined somewhat rapidly in activity and was not satisfactorily regenerated with air.