Electrochemistry: The Senior but Underused Area of Surface Science

Electrochemistry ought to be regarded as a vintage area of interfacial science. It has long been known that the application of an external potential at a (conducting) solid-solution interface enhances the reactivities of adjacent chemical species. Catalytic reactions activated by control of potential at the electrode-solution interface thus serves as an alternative to activation by control of temperature at gas-solid interfaces. In fact, on the singular basis of catalytic selectivity, the electrochemical route towards synthesis and catalysis should be favored over the thermal approach because the application of elevated temperatures activates other reaction pathways. For a two-electron reaction, for example, a potential change of only half a volt can lead to a 10 8 -fold increase in reaction rate. Assuming an activation energy of 75 kJ mole -1, this enormous rate increase can be effected only at temperatures above 600 K. Such drastic conditions invariably lead to a wide spectrum of thermal excitations