g TRANSACTIONS OF WAGNER 



CATALYSIS IN THE INORGANIC FIELD 



In some few instances, however, the effects of adjacent bodies were so 

 striking as to compel early attention. Until recent years, the multipHcation 

 of such instances has been slow. Such action or influence of an adjacent 

 body may be covered by the word "catalysis," introduced by Berzelius in 

 1834. The influence of the adjacent body, like the influence of the main sub- 

 stances in a reaction, is profoundly affected by the state of subdivision of the 

 adjacent body. When potassium chlorate is heated in a silica test-tube, for 

 example, the decomposition occurs at an elevated temperature and irregularly. 

 If finely ground silica is first mixed with the chlorate, the chlorate decomposes 

 more rapidly and more oxygen is obtained in a given time without heating to 

 as high a temperature. 



Although contact and a state of fine subdivision favor "catalysis," they 

 are not the most fundamental requirements. These most fundamental re- 

 quirements are the problem of today. Apparently, the nature of the adjacent 

 body is capable of exerting the preponderating influence. In catalysis, the 

 adjacent body merely alters the rate of a reaction that also occurs of itself, 

 and in so doing the catalyst does not increase or decrease in amount. Most 

 known catalysts accelerate changes; some retard changes and are called 

 "negative catalysts." 



It is important to answer the question why substances may be brought into 

 intimate contact without noticeable chemical action resulting. Two answers 

 may be given: (i) The two bodies may have httle or no chemical attraction or 

 affinity for each other, as, for example, fluorin and oxygen. (2) The two bodies 

 may have an affinity for each other but the rate at which they react may be too 

 slow to produce noticeable amounts of product in the period of observation. 



In the first instance, no catalyst could have any effect. Only in the second 

 instance could catalysis occur. The reason for this statement lies in the laws of 

 energy. Mechanical (or available) energy can never spontaneously increase. 

 It is clear that if catalysts could cause reactions otherwise impossible because 

 no chemical affinity existed between the two bodies in contact, we might, 

 by a suitable selection of catalysts, arrange cyclic chemical processes that would 

 continue to supply available energy so long as energy of any kind remained in 

 the system. But experience has taught that the molecular motions and strains 

 that constitute thermal energy cannot be so treated by the aid of catalysts, 

 or by any other aid whatsoever. 



Historically, catalysis is not a new phenomenon. Processes of fermenta- 

 tion were known to the ancients, and these involve catalysts. In fermentation 



