179.    BEECK, O., RITCHIE, A. W., AND WHEELER, A.  Adsorption of Hydrogen on Nickel Catalysts.  I.  Effect of Sintering.  Jour. Colloid Sci., vol. 3, 1948, pp. 505-510; Chem. Abs., vol. 43, 1949, p. 2079.

                  High-vacuum-evaporated Ni films prepared at 23° by the method previously described adsorb H₂ virtually instantaneously.  There is little difference in the amount adsorbed at –196° and at room temperature.  This is in marked contrast to the results obtained with Ni catalysts prepared from NiO by H₂ reduction, which sorb H₂ slowly at room temperature in amounts 2-4 times the amounts adsorbed at –196°.  If the vacuum-evaporated films are sintered at 100°-400°, slow sorption of H₂ is observed.  The ratio of slowly sorbed H₂ to rapidly adsorbed H₂ increases with increasing sintering temperature.  The so-called “activated adsorption” of H₂ on Ni is not adsorption on the metal surface but is slow sorption of H₂ into the interior of the metal structure.  The adsorptive capacity of Ni indicated by chemisorption of CO or physical adsorption of Kr corresponds to the capacity for rapid H₂ sorption, chemisorption, and for catalytic reactions such as C₂H₄ hydrogenation but does not correspond to the capacity for slow sorption.