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=βp1/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.