3464.     TROPSCH, H., SCHELLENBERG, A., AND VON PHILIPPOVICH, A.  [Reduction of Carbon Monoxide.]  Ges. Abhandl. Kenntnis Kohle, vol. 7, 1925, pp. 63-67; Chem. Abs., vol. 21, 1927, p. 2550.

        Formation of CH₄ from a mixture of CO (1 vol.) and H₂ (3 vol.) in contact with Ni, which normally occurs quantitatively at 240°-250°, is greatly diminished by adding NH₃ to the gas mixture.  Neither formaldehyde nor hexamethylenetetramine was formed, and the final mixture contained 13% CH₄, 15% CO, 64% H₂, and 8% Ni.  With a Ni catalyst that had been treated with alkali, the same gas mixture yielded at 400° and atmospheric pressure, 53% CH₄ and 1.1% of unsaturated hydrocarbons, the only liquid reaction product being H₂O.  The same reaction occurred with a Ni catalyst that had not been treated with Alkali, except that no unsaturated hydrocarbons were formed.  A mixture of equal volumes of CO and H₂ in contact with an alkaline Ni catalyst at 400°, deposited much C.  With a feebly alkaline catalyst, the final gas contained 27% CO₂, 2% CO, 26% H₂ and 45% CH₄, while, with a more strongly alkaline catalyst, it contained 11% CO₂, 29% CO, 50% H₂, and 9% CH₄.  With both alkaline and neutral catalysts, the CH₄ contained 1.5% of higher homologs, reckoned as ethane.  A mixture of equal volumes of CO₂ and H₂, in contact with neutral Ni at 400°, gave a final gas containing 10% CO₂, 42% H₂, and 48% CH₄, while with alkaline Ni it gave 7% CO₂, 70% H₂, and 23% CH₄.  In no case could MeOH be detected.