The Crystallographic Orientation and Surface Modification Effects in Electrocatalysis

A paramount role of surface structure and composition on the kinetics of electrocatalytic reactions has been realized with the establishment of electrocatalysis as a science. Consequently, a variation in the surface structure, and a modification of surface composition is expected to result in a considerable alternation of the electrocatalytic properties of electrodes. Reliable data on the role of surface structure have not been obtained until recently in the work with the single crystal surfaces. The effect of crystallographic orientation of electrode surfaces on kinetics of electro chemical reactions has been definitely established in the oxidation of small organic mclecules':" and oxygen reductionš-" on well-prepared single crystal surfaces. A modification of surface properties by foreign metal adatoms, obtained by the underpotential deposition, has been shown to produce striking catalytic effects on various electrode reactions (Ref. 7 and references therein). This is a simple way to modify surface properties, which may have an applicative potential.