Scanning tunneling microscopy and electrochemistry

The experimental gap existing between surface science and heterogeneous chemical kinetics applies also to electrochemistry. Difficulties for modelling the electrode surface topography under equilibrium and non-equilibrium conditions, particularly for solid electrodes, are presented. Attention is focussed on structural problems of metal/solution interfaces encountered in corrosion and passivation of metals and in electrocatalysis, although the analysis also extends to metal electrodeposition and to semiconductor/solution interfaces. STM has already provided important imaging of preferred oriented platinum electrode surfaces as well as large surface area platinum electrodes exhibiting practically no diffusional and ohmic polarization effects. Possible applications of STM to underpotential deposition of metals and to chemically modified electrodes are envisaged among others. Some future perspectives of STM for electrochemistry are advanced.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada