2433.     NEUMANN, B., AND BILJCEVIC, P.  [Catalytic Preparation of Formaldehyde.]  Ztschr. angew. Chem., vol. 40, 1927, pp. 1469-1474; Chem. Abs., vol. 22, 1928, p. 760.

        Theoretical considerations show that in CO₂-H₂ mixtures at equilibrium only traces of HCHO can be present.  Only traces were produced in porcelain and SiO₂ tubes at varying temperatures without catalyst or with the following:  Silica-gel, Ce₂O₃, V₂O₃, NaOH-CaO, CuCl₂, activated C and Cl₂, CuCl₂, on silica-gel, Pd sponge, hopcalite, Fe-Pd, Ni-Fe-Pd, Fe-Co, Mn-Co, and others.