The adsorption of hydrogen on nickel catalysts. I. The effect of sintering

Stepwise Adsorption of Krypton on Nickel

“…Samples out gassed at 200°y ielded smooth isotherms with reasonably linear BET plots. The chemically precipitated nickels give characteristic type II sigmoidal curves similar to the results reported by O. Beeck, et al, 6 for krypton on evaporated nickel films. The carbonyl nickel isotherms, such as those of Fig.…”

“…The rate of disappearance of diacetylene when 94.5 96.6 " A trace of vinylacetylene was detected at 8 milliseconds but none at longer contacts. 6 Trace. heated to 1200°at a concentration of 0.1 mole % is shown in Fig.…”

Heat of adsorption of oxygen on uranium dioxide at ‒183° C

“…That a gas molecule approaching the surface does not adsorb on a 20 kcal site because of the existence elsewhere on the surface of a 50 kcal site seems unlikely. Neither does it seem probable, on first sight, th a t at -183° C chemisorption taking place on a 20 kcal site is followed by removal of the adsorbed molecule from th a t site to a 50 kcal site, although Beeck (1950) postulated a mobile chemisorbed film of hydrogen on metallic nickel at -183° C despite an observed heat of adsorption of some 30 kcal/mole.…”

“…A similar slow reaction has been reported by Beebe & Dowden (1938) from experiments on the adsorption of various gases including oxygen on chromic oxide, and by Beebe & Stevens (1940) from work on iron catalysts. This slow reaction taking place on the surface is to be distinguished from slow adsorption from the gas phase (Garner, Stone & Tiley 1952) or even of slow sorption into the interior of the solid (Beeck, Ritchie & Wheeler 1948;Beeck, Givens & Ritchie 1950). The slow reaction has also been observed on a uranium dioxide sample which had been reduced at all stages of its preparation in hydrogen and whose surface could not have been contaminated with carbon, which can therefore not be responsible for the slow reaction.…”

Molecular Hydrogen and Metallic Surfaces.

“…There seems little doubt now that chemisorption of hydrogen molecules on to a clean metal surface is not the basis of "activated adsorption." Slow or activated adsorption on metals where it is observed may be attributed to displacement of impurities (2,71), sorption into the lattice (13), or possibly surface diffusion of atoms into the interior of porous solids (7,87).…”