2682.     ---------------.  [PICHLER, H., AND BUFFLEB, H.]  [Synthesis of Free Formic Acid From Carbon Monoxide and Water.]  Brennstoff-Chem., vol. 23, 1942, pp. 73-77; Chem. Age, vol. 53, 1945, pp. 463-468; Chem. Abs., vol. 36, 1942, p. 4474.

        Formation of formic acid through the direct action of CO and H₂O under pressures up to 2,000 was investigated.  At each temperature, a definite state of equilibrium exists between the concentration of liquid formic acid and CO pressures.  Certain mineral acids and salts (Cu₂SO₄, CuCl₂) and especially H₂S and H₃PO₄ are suited as catalysts.  The salts under the conditions of the reaction are reduced to the mineral acids.  The optimum conditions for formic acid synthesis are determined.