2468.     NIKITIN, N. I.  [Absorption of Hydrogen and Carbon Dioxide by Pyrophoric Iron, Nickel, and Cobalt.]  Jour. Russian Phys.-Chem. Soc., vol. 58, 1926, pp. 1081-1094; Chem. Abs., vol. 22, 1928, p. 8.

        Finely divided Fe, obtained by the action of H₂ on the carbonate at 515°-525°, adsorbed H₂ at –185° according to the equation a=βp^1/n.  No adsorption was observed at –80° and +16°, while at 330° the gas diffuses through Fe.  The adsorption isotherm of Ni at 19° is parallel to the axis of pressures showing compound formation.  No combination occurs at –185°, since the corresponding isotherm begins at the origin.  The 336° curve crosses that for 19°; its lower portion represents the dissociation of the Ni and H₂ compound.  The above equation holds for Fe and CO₂ at 18° (1/n=0.207).  Readsorption, after evacuating the system at 500°, was much smaller although similarly represented by a straight line; a slow reaction occurs at 500°.  Ni adsorbs little CO₂ at 14° and 335°; the gas is only partly recovered by evacuation.  Erratic results were obtained with Co prepared at 340°.  A sample reduced at 525°-550° exhibited a continuous adsorption isotherm for CO₂ at 14°.  Co lies between Ni and Fe as an adsorbent of CO₂.