Scanning electrochemical cell microscopy (SECCM) is a new pipette-based imaging technique purposely designed to allow simultaneous electrochemical, conductance, and topographical visualization of surfaces and interfaces. SECCM uses a tiny meniscus or droplet, at the end of a double-barreled (theta) pipette, for high-resolution functional imaging and nanoscale electrochemical measurements. Here we introduce this technique and provide an overview of its principles, instrumentation, and theory. We discuss the power of SECCM in resolving complex structure-activity problems and provide considerable new information on electrode processes by referring to key example systems, including graphene, graphite, carbon nanotubes, nanoparticles, and conducting diamond. The many longstanding questions that SECCM has been able to answer during its short existence demonstrate its potential to become a major technique in electrochemistry and interfacial science.

The electrochemical oxidation of ethanol as well as its irreversible adsorption on platinum single crystal electrodes has been studied in an alkaline solution. In addition, the adsorbed species in the ethanol oxidation reaction were also studied by means of surface enhanced Raman spectroscopy (SERS) on a platinum film electrode. It was found that the oxidation of ethanol is very sensitive to the electrode surface structure: a higher concentration of low-coordination sites increases the current, lowers the overpotential required and lowers the deactivation rate. Furthermore, the terrace length also affects the amounts and the nature of the adsorbed species: on Pt (110), only CO_ad was observed, whereas adsorbed CH_x could only be found on electrode surfaces with (111) terrace sites. Based on the results here, a model for the ethanol electro-oxidation reaction in alkaline media is presented, and the differences with the same reaction in acidic media are pointed out.