Infrared Reflectance Spectroscopy

The structure of the electrode/electrolyte interface plays an important, growing role in electrochemistry and electrocatalysis. On one hand, the distribution of charged particles and dipolar molecules in the double layer (i.e., the transition region between the surface of the metal electrode and the bulk of the electrolyte solution) under the combined influence of diffusion and potential gradients determines the potential barrier, which strongly influences the rate of electrochemical reactions, i.e., reactions involving charge transfer through the interface.(1) On the other hand, many electrode reactions proceed through adsorbed intermediates, which are produced during chemisorption of the reacting molecules (the so-called electroactive species) on the electrode surface. The mechanisms of these electrocatalytic reactions will therefore greatly depend on the nature of the electrode material, which determines the structure of the adsorbed intermediates(2).