568.    ---------------.[CHUFAROV, G. I., AND TATIEVSKAYA, E. P.]  [Comparison of Initial Velocities of Reaction of Oxides of Iron With Hydrogen and Carbon Monoxide and Their Mixtures.]  Jour. Phys. Chem. (U.S.S.R.), vol. 8, 1936, pp. 933-942; Chem. Abs., vol. 31, 1937, p. 2075.

     Near 500° the reduction of hematite is much slower by CO than by H₂.  At higher temperatures, 800°, the ratio of the velocities approaches the ratio of impinging molecules of the 2 gases.  As a result of the smaller number of active centers at higher temperatures the absolute values of the reduction velocities are small.  At 500° the presence of CO in mixtures of CO+H₂ decreases the reduction below that expected for the partial pressure of H₂, because of adsorption of CO on a large number of the active centers.