725.    DOLGOV, B. N., AND BOCHAROVA, E. M.  [Methanol Synthesis.  IV>  Catalytic Oxidation of the Synthetic Methanol to Formaldehyde].  Khim. Tverdogo Topliva, vol. 3, 1932, pp. 406-418; Chem. Zentralb., 1934, I, p. 2652; Chem. Abs., vol. 28, 1934, p. 5805.

     According to the experiments described in detail, passage of the gas mixture over porous surfaces (glass, porcelain, C) yields minute amounts of HCHO.  The metallic catalysts, except Ag and Cu, are of little use.  The yields are slightly higher when the catalysts are compressed in the reaction tube.  Metal oxides cannot be used, while catalysts prepared from Cu disks, which are placed close together, give a HCHO yield up to 42%.  A catalyst composed of CuO alone or together with an activator gives CH₂O yields of 21-42%.  The best results were obtained with Th and U catalysts, which yielded up to 41-42% of CH₂O.  The apparatus used is described, and the numerical data are tabulated.