2027.     ---------------.  [KWAN, T.]  Research on Pure Iron and Synthetic Ammonia Catalyst by Means of Hydrogen Adsorption. Jour. Research Inst. Catalysis, vol. 1, 1949, pp. 100-109; Chem. Abs., vol. 44, 1950, p. 4304.

        Adsorption isotherms of H at pressures between 10^-4 and 1 mm. Hg on pure Fe and synthetic NH₃ catalyst were determined at 0°, 25°, 50°, and 100°.  Differential heats of adsorption diminish continuously from 17.5 kg.-cal. per mol. at the lowest pressure to 5 kg.-cal. per mol. at the highest pressure.  Calculations from the rate of decrease of the differential heat of adsorption yield surface areas 70 and 14 times, respectively, the Brunauer-Emmett-Teller area of Fe and synthetic NH₃ catalysts and are in contrast to results on Ni and Co powders.  To account for these results it is assumed that 2 different types of crystal planes are involved in the adsorption, and a modified expression is derived for the variation of the heat of adsorption on this basis.