The role of surface crystalline heterogeneities in the electrooxidation of carbon monoxide adsorbed on Rh(111) electrodes in sulphuric acid solutions

The electrooxidation of CO saturated adlayers has been studied on three different rhodium electrodes: Rh(111), Rh(554) and electrochemically disordered Rh(111). It has been found that the kinetics of the CO stripping process is sensitive to the long-range order of the (111) domains. The more ordered the surface, the slower the oxidation proceeds. This provides a criterion for the assessment of the surface quality. It is noteworthy that the Rh(111) blank voltammogram does not show significant changes upon structural modification of the electrode surface: the voltammetric profiles for Rh(111) and Rh(554) in 0.5 M sulphuric acid are virtually identical. (C) 1997 Elsevier Science S.A.