Electrocatalysis surface reaction free

Several reviews addressing the polarization behavior, d ion adsorption, competition between Cr adsorption and OH codeposition, oxide film formation, and cr ion discharge, as well as the kinetic aspects of the reaction on various oxide-covered and oxide-free surfaces that have been investigated during the past 15 years, have been published (55/, 333-338). Of these, particular mention should be made of Refs. 555, 335, 336, and 439-441, where the basic aspects of the properties of oxide electrodes and the kinetic aspects of oxide film formation in relation to Cl adsorption and the kinetics of Cr ion discharge were addressed. Mechanistic aspects of chlorine evolution were critically analyzed recently in an excellent article by Trasatti (338). In this article, the focus is primarily on the nature and characterization of the adsorbed intermediates partipatingin the course of CI2 evolution and their role in the electrocatalysis of the chlorine evolution reaction. As with the OER, in aqueous solutions CI2 evolution takes place on an oxidized surface of metals or on bulk oxide films, so that their surface states often have to be considered in treating the electrocatalysis of the reaction. 

Anodic Reactions in Electrocatalysis -Oxidation of Carbon Monoxide, Fig. 3 Cyclic voltammogram of a rotating polycrystalline Pt disk electrode in CO saturated 0.1 M H2SO4. Potential sweep rate 0.050 V s rotation rate 900 rpm. The inset shows the integrated IR peak of COj,j plotted versus the position on the electrode for the applied current of 0.3, 1.4, 1.5, 1.7, 1.75, and 1.8 mA left to right and top to bottom). The red color indicates a high CO j coverage and the blue a CO-free surface (Reproduced from Ref [28] with permission of the American Chemical Society)... 

---