ABSTRACT
An understanding of the nature of the surface orbitals of a catalytically active site is essential for determining the molecular processes which can take place on such sites. This type of information can provide a means of correlating a given type of catalyst: substrate interaction with the formation of a specific product, data which could eventually lead to the ability to design new catalyzed processes from first principles. However, data have been reported which show that while reactions involving C—C bond hydrogenolysis or hydrocarbon isomerizations occur on ensembles of atoms on the faces of the metal crystallites present on supported metal catalysts, most other catalytic reactions, particularly those involving C-H bond breaking or formation, take place on single-atom active sites, probably the more coordinately unsaturated corner atoms. A knowledge of edge and corner atom activity, however, is essential for the detailed understanding of most present catalytic processes and the development of new ones.
