2238.     MERCK, F., AND WEDEKIND, E.  [Magnetic Analytic Investigation of Cobalt Oxide as Catalyzer of Carbon Monoxide Combustion at Room Temperature.]  Ztschr. anorg. Chem., vol. 186, 1930, pp. 49-74; Chem. Abs., vol. 24, 1930, p. 2036.

        It is concluded that the cobaltic oxide catalyzer consists essentially of 2 crystalline phases, CoOOH and CO₃O₄, Co₂O₃ being chiefly converted into the latter.  Of these 3, the components CoOOH and Co₃O₄ are catalytically ineffective.  The cobaltic oxide in the Co₃O₄ lattice is superficially reduced by the diluted CO.  Magnetic measurements were made by Wedekind’s microchemical method (see abs. 3619) and show that magnetism increases in going from hydrate to oxide.  For Co₃O₄, x is about 32 x 10^-6 and varies relatively little as the titratable O content varies.  In the transformation from hydrate to oxide, an active intermediate state is present, characterized by a dependence of susceptibility upon field strength.  This vanishes on sintering and also on aging with partial reconversion into hydrate.  At room temperature the hydrate is more stable than oxide+H₂O.