2715.     PLOTNIKOV, V. A., AND POSPEKHOV, D. A.  [Hydrogen Adsorption on Methanol Catalysts.]  Mem. Inst. Chem., Ukrain, Acad. Sci., vol. 1, 1934, pp. 153-167 (in German, pp. 169-170); Chem. Abs., vol. 29, 1935, p. 7741.

        H₂ adsorption was studied on a Cu-ZnO-Cr₂O₃ catalyst reduced in H₂ at 200°-300° and still containing bound water.  In the range 200°-300°, a higher temperature of evacuation increases subsequent H₂ adsorption (removal of more adsorbed H₂O).  Successive adsorption and desorption lead to a greater mass of adsorbed gas each time.  Saturation is reached only above 1 atm.  The catalyst evacuated at 300° (anhydrous) shows lower but completely reversible adsorption.  Fatigue is held to be due to dehydration.  Adsorption is greater in catalysts rich in ZnO-Cr₂O₃; these also show fatigue most rapidly.  No direct simple relation exists between the adsorption of H₂ and the activity at a given temperature.  The effect of the temperature of evacuation on the H₂ adsorption is very slight for a 91% Cu catalyst, only 10% from 225° to 300°, but very great for catalysts of lower Cu content 2.5 times from 225° to 290° for a 60% Cu catalyst.  Heat of adsorption is about 1,500 cal. per mol. of H₂.