977.    FISCHER, F., AND BANGERT, F.  [Formation of Carbides Decomposable by Water From Manganese Oxide and Methane at Relatively Low Temperatures.]  Brennstoff-Chem., vol. 10, 1929, pp. 261-265; Ges. Abhandl. Kenntnis Kohle, vol. 9, 1930, pp. 694-706; Chem. Abs., vol. 24, 1930, p. 3453.

     An excess of CH4 was passed over pulverized oxide (MnO2 or Mn3O4) heated to 800-1,000, both with and without admixture of other metallic oxides.  Carbides formed were decomposed by H2O and by HCl, and the hydrocarbons resulting were measured and analyzed.  Of the admixed oxides, BaO and Al2O3 alone favored formation of carbides decomposable by H2O.  Formation of carbides decomposed by HCl was favored by NiO, Cr2O3, and Fe2O3.  CeO2, CaO, TiO2, CuO, V2O5, and K2CO3 exerted little or no influence.  The following are conclusions reached:  (1) Carbides are formed by passing CH4 over the Mn oxides at 800-1,000; (2) admixtures of foreign oxides strongly affect the properties of the carbides formed; (3) in the absence of heavy metal oxides, the Mn oxides heated to 800 and above CH4 give a carbide that will yield 90% of its C as gaseous hydrocarbons on decomposition with H2O; (4) existence of a previously unknown Mn carbide (Mn5C2)x is indicated.