Electrochemical Scanning Probe Microscopies in Electrocatalysis

Improvements toward highly efficient electrochemical energy conversion require a detailed understanding of the underlying electrochemical processes at electrified solid-liquid interfaces. In situ and in operando studies by means of electrochemical scanning probe microscopy (EC-SPM) have become indispensable experimental tools due to their capability of resolving surface topography down to the atomic level even within the harsh environment of electrolytes. EC-SPM methodologies have thus contributed tremendously to the current understanding of electrocatalysis. In this review article, recent achievements in complementary EC-SPM techniques, namely electrochemical scanning tunneling microscopy (EC-STM), electrochemical atomic force microscopy (EC-AFM), scanning electrochemical potential microscopy (SECPM), and scanning electrochemical microscopy (SECM), are discussed with particular focus on electrochemical phenomena important for the field of electrocatalysis. The currently available options for obtaining insight on local chemical composition and local reactivity as well as important electrocatalytic model systems are considered. In addition, the application of EC-SPM methods to metal ion batteries is addressed.