Development of kinetic aspects in catalysis research

I am greatly honored to have been invited to give the historical introduction to the 4th ISISS, since such prominent speakers as Emmett, Muller, and Tompkins have been my predecessors in this function. I have chosen the subject of the historical development of kinetic research in catalysis because I believe that we find ourselves at a turning point, or at least a kinkpoint, in this research. In his famous definition of a catalyst at the end of the last century, Ostwald gave for the first time a certain viewpoint to catalysis in the system of chemistry. He defined catalysis as a question of reaction velocity. Since 1928 when I was called by the late Professor Eggert to give a report on the results of heterogeneous gas reactions in "Ergebnisse der exakten Naturwissenschaften", 1 I have always emphasized the view that catalysis is essentially a velocity problem and that therefore reaction kinetics is the natural method for its investigation. Today, I report the results which this type of approach has given to date. I believe that it is quite a respectable volume of knowledge; however, I equally believe that the modem development of solid state physics and especially surface physics has led to a point where for the first time investigations other than those of reaction kinetics arc giving basically new information about the catalyst and adsorbed substances. This reveals new aspects of catalysis itself and will continue to do so. Dr. G. Ertl will undoubtedly give examples.