[boswell] catalysis OF HYDROGENATION BY NICKEL 9 



(1) Does this adsorption of hydrogen during the reduction of 

 nickel oxide continue after long reduction? 



(2) Is it possible to reduce nickel oxide so that it loses all its 

 oxygen, by heating at 275° in a current of hydrogen? 



(3) Will the product of the reduction of nickel oxide at 275° by 

 hydrogen and containing a considerable amount of adsorbed hydrogen, 

 hydrogenate ethylene alone at 150° in the absence of free hydrogen? 



(4) Will the product of the lengthy reduction of nickel oxide by 

 hudrogen at 275° catalyse the hydrogénation of ethylene by free 

 hydrogen ? 



In this experiment approximately 2f-3 grams of nickel oxide 

 on asbestos was placed in tube d of the apparatus. The air in the 

 apparatus was displaced by hydrogen in the cold and the burettes 

 filled with a measured volume of hydrogen. The hydrogen was 

 passed back and forth, the tube d being heated to 275°C. and the 

 water evolved measured at intervals of 24 hours after cooling to room 

 temperature. Care was taken to exclude air from the apparatus 

 during the disconnection and connection of the U tubes. Follow- 

 ing are the results obtained: 



Thus, after nine days' reduction at 275°, hydrogen is still adsorbed 

 in considerable quantity over and above the hydrogen required to 

 form the water evolved. It was also found that there was the same 

 relatively large disappearance of hydrogen on standing at room 

 temperature each night. Hydrogen was passed back and forth for 

 one hour every morning at room temperature in order to carry over 

 the water evolved during the night. The volumes under the headings 

 " H at end c.c." corresponds to the reading on the burettes each 

 morning after this passage back and forth for one hour at room 

 temperature. Evidently after nine days' reduction there is still con- 



