2984.     RUMFORD, F.  Correlation of Adsorption and Catalytic Activity.  I.  Hydrogen Adsorption on Zinc-Chromium Catalysts.  Jour. Roy Tech. Coll. (Glasgow), vol. 4, 1939, pp. 427-440; Chem. Abs., 33, 1939, p. 5269.

        Relation between catalytic activity and activated adsorption was investigated, but results are inconclusive.  ZnO suspensions were mixed with chromic acid solution, dried at temperature below 110°, and screened to 10-40 mesh.  Catalysts were reduced by CH₃OH vapor in the presence of airfree N₂.  The method of operation was to introduce into the catalyst bulb a known weight of catalyst, approximately 5 cc in volume.  The whole system then was closed, the apparatus evacuated, and the catalyst temperature raised to 500°.  H₂ then was admitted to atmospheric pressure level and left for 15 min.; after this, the gas was removed again, and the catalyst was maintained at the lowest possible pressure for another 15 min.  H₂ was then removed and the catalyst cooled to the desired temperature.  H₂ gas for test then was admitted in 3 portions; this brought the pressure to levels of 250, 500, and 760 mm. of Hg, respectively.  After each addition, the adsorption was continued for 20 min.  The quantities of gas adsorbed varied 0.5-2.0 cc.  By use of the method previously outlined, a series of adsorptions at 300°-500°, with 50° intervals was made.  Plotting the results shows the catalysts fall into 2 classes -- first, those in which a definite type of activated adsorption appears 300°-350°, and second, those in which a somewhat less definite change appears some 50° higher.  Use of these measurements in calculating heats of adsorption or of activation are disappointing.  The effect of CO on the mechanism of adsorption is not known.