50.    ANDERSON, R. B., SCHULTZ, J. F., SELIGMAN, B., HALL, W. K., AND STORCH, H. H.  Studies of the Fischer-Tropsch Synthesis.  VII.  Nitrides of Iron as Catalysts.  Jour. Am. Chem. Soc., vol. 72, 1950, pp. 3502-3508; Chem. Abs., vol. 44, 1950, p. 10299.

               Conversion of Fe in reduced synthetic ammonia-type catalysts to nitrides by ammonia treatment greatly increased their activity in the Fischer-Tropsch synthesis.  All tests described in the paper were performed with a catalyst prepared by the electrical-fusion method and having the composition: Total Fe 67.4%, ferrous Fe 21.7%, MgO, 4.61%, K₂O, 0.57%, SiO₃, 0.71%, and Cr₂O₃, 0.65%.  Catalysts converted to e-phase nitrides yielded a product of lower average molecular weight containing greater yields of gaseous hydrocarbons and oxygenated molecules than those products from corresponding reduced catalysts.  In the synthesis, nitrided Fe catalysts appear to resist oxidation and deposition of free C and have a greater stability and longer life.