824.    ---------------.  [EMMETT, P. H., AND BRUNAUER, S.]   Application of Polanyi’s Potential Theory to the van der Waals Adsorption of Gases on Iron-Synthetic-Ammonia Catalysts.  Jour. Am. Chem. Soc., vol. 57, 1935, pp. 2732-2733; Chem. Abs., vol. 30, 1936, p. 1291.

      Potential-volume curves for the adsorption of N and A on a single promoted Fe synthetic-NH3 catalyst are given.  They seem to represent the isotherms very closely throughout the entire pressure range covered including the region concave to the pressure axis where probably less than a molecule layer of gas exists, the linear portion that has been postulated to represent the building up of a 2d layer of gas on the catalyst surface, and the higher-pressure portion, which is convex to the pressure axis and, which, it is generally believed, represents the condensation of the gas to liquid in the capillaries of the adsorbent.  The potential curves exhibit no variation with temperature, the –183° and –195.8° points falling on the same curve.